1
If the 2nd and 5th terms of a G.P are 6 and 48 respectively, find the sum of the first for term

Answers

Answer 1

If the first term is [tex]a[/tex], then the second term is [tex]ar[/tex], the third is [tex]ar^2[/tex], the fourth is [tex]ar^3[/tex], and the fifth is [tex]ar^4[/tex].

We're given

[tex]\begin{cases}ar=6\\ar^4=48\end{cases}\implies\dfrac{ar^4}{ar}=r^3=8\implies r=2\implies a=3[/tex]

So the first five terms in the GP are

3, 6, 12, 24, 48

Adding up the first four gives a sum of 45.

If you were asked to find the sum of many, many more terms, having a formula for the n-th partial sum would convenient. Let [tex]S_n[/tex] denote the sum of the first n terms in the GP:

[tex]S_n=3+3\cdot2+3\cdot2^2+\cdots+3\cdot2^{n-2}+3\cdot2^{n-1}[/tex]

Multiply both sides by 2:

[tex]2S_n=3\cdot2+3\cdot2^2+3\cdot2^3+\cdots+3\cdot2^{n-1}+3\cdot2^n[/tex]

Subtract this from [tex]S_n[/tex], which eliminates all the middle terms:

[tex]S_n-2S_n=3-3\cdot2^n\implies -S_n=3(1-2^n)\implies S_n=3(2^n-1)[/tex]

Then the sum of the first four terms is again [tex]S_4=3(2^4-1)=45[/tex].


Related Questions

Two cards are selected at random from a standard deck of cards. What is the probability that you select a king or a queen? (If your answer will reduce, you should reduce it.) Also show you're work

Answers

Answer:

2/13

Step-by-step explanation:

In a standard deck of cards, there are 52 cards total, 4 kings, and 4 queens.

Probability is calculated by (number of favorable outcomes)/(number of possible outcomes), so our probability would be 8/52, which can be simplified to 2/13.

Hope this helps!

The population of a certain type of seahorse grew by 13% from year to year.

Should the be modeled linear function or Exponential function ?

Answers

Answer:  Exponential function

Step-by-step explanation:

A linear function is the form[tex]f(x)=mx+c[/tex] , where m is the constant rate of change of y with respect to x and c is the y-intercept.

An exponential growth function is in the form [tex]f(x)=A(1+r)^x[/tex], where r is the rate of growth (generally in percent) and A is initial value.

If the population of a certain type of seahorse grew by 13% from year to year, then the rate of growth is 13% .

Hence it is an exponential equation.

GIVING BRAINIEST (open attachment)

Answers

Answer:

1/19

Step-by-step explanation:

Let's say there are x yellow cubes.

That means there are 3x blue cubes.

Therefore, there must be 15x green cubes.

In total: we have 19x cubes.

Therefore the probability of a cube being yellow is x / 19x

which simplifies to 1/19

Answer:

1/19

Step-by-step explanation:

Solution:-

- First we will define the distribution of colors in the bag.

- We will use variable:

                     x: the number of yellow cubes in bag

- The following color distribution can be made by using the data given in the question:

                   Color                     Number of cubes

                   Yellow                               x

                   Blue                                  3*x = 3x

                   Green                               3x*5 = 15x

          ======================================

                  Total                                 19x

          ======================================

- Sarah is to draw a cube from the bag. We are to determine the probability that the randomly picked cube would be yellow. We will denote our event as randomly picking a yellow cube from the bag with a defined finite distribution.

         p ( Picks Yellow cube ) = [ Number of yellow cubes ] / [ Total cubes ]

         p ( Picks Yellow cube ) = [ x ] / [ 19x ]

         p ( Picks Yellow cube ) = 1 / 19   .... Answer

In which quadrant or on which axis do each of the points (2, 3 ), ( 5, -6 ), ( 2,0 ) , ( -5, 2 ), (-2,-4), (0,-2).

Answers

from the above picture

2,3 = 1 quadrant

5,-6 = 4 quadrant

2,0 = on x axis

-5,2 = 2 quadrant

-2,-4 =3 quadrant

0,-2 = on y axis

Find the area of this shape.
4 cm
2 cm
4 cm
4 cm
-
1
5.75 cm
1
1
The area of the shape is __
square centimeters.

Answers

Answer:

shape AREA= 35cm^2

Step-by-step explanation:

you should know that this shape is a combination of triangle and trapezoid. therefore you have to find the area of each shape and add them.

A=h/2(b1 + b2) for trapezoid

A=2/2((4+4)+4)

A=1*12

A=12cm^2

A=bh/2. for TRIANGLE

A=1/2((4+4)*5.75)

A=1/2(46)

A=23cm^2

shape AREA= triangle AREA + trapezoid AREA

shape AREA=12cm^2 + 23cm^2

shape AREA= 35cm^2

what is the domain of the function represented by the graph.?​

Answers

Answer:

  all real numbers

Step-by-step explanation:

There is nothing on the graph to indicate the function is undefined for any values of x. The domain is all real numbers.

Answer:

Domain is all real numbers.

Step-by-step explanation:

The domain of a quadratic function in standard form is always all real numbers, meaning you can substitute any real number for x.

Paige launched a ball using a catapult she built. The
height of the ball (in meters above the ground) t seconds
after launch is modeled by
h(t) = -5t2 + 40t
Paige wants to know when the ball will hit the ground.
1) Rewrite the function in a different form (factored
or vertex) where the answer appears as a number in
the equation.
h(t) =
2) How many seconds after launch does the ball hit
the ground?
seconds

Answers

Answer:

5 seconds ma boii

Step-by-step explanation:

i just took tha test

Answer:

1) h(t) = -5t(t - 8)

t - 8 = 0, so

2) t = 8 seconds

Step-by-step explanation:

Previous problem : From Andy's house to Billy's hometown you can travel by 3 roads. And to get from Billy's hometown to Willie's house you can travel by 5 roads. How many possible ways are there to travel from Andy's house to Willie's house? From Dan's ranch one road is built to get to Andy's house and two roads are built to get to Willie's house (see previous problem). How many way are there now to get from Andy's house to Willie's house?

Answers

Answer:

Andy's house to Billy's hometown 15 ways

Andy's house to Willie's hometown 2 ways.

Step-by-step explanation:

Andy's house to Billy's hometown there are 3 roads. There 5 road from billy's hometown to Willie's house . In total there will be 15 ways to travel which is calculated by 3 * 5. For traveling to Willie's hometown there will be two ways. There are two roads that are built to get to Willie's house.

WILL MARK BRAINLIEST!!!!

Answers

Answer:

See below.

Step-by-step explanation:

SQUARE:

The area of the square is:

[tex]9x^2-12x+4[/tex]

Factor it:

[tex]=9x^2-6x-6x+4\\=3x(3x-2)-2(3x-2)\\=(3x-2)(3x-2)\\=(3x-2)^2[/tex]

Remember that all four sides of a square is equal. The area is simply the side squared. Therefore, all four sides of the square measure (3x-2).

RECTANGLE:

[tex]25x^2-16y^2\\[/tex]

Factor it. This resembles the difference of two squares, where:

[tex](x-a)(x+a)=x^2-a^2[/tex]

[tex]25x^2-16y^2\\=(5x)^2-(4y)^2\\=(5x-4y)(5x+4y)[/tex]

This cannot be simplified further. Note that the sides of rectangles doesn't necessarily have to be the same.

The dimensions of the rectangle is:

(5x-4y) by (5x+4y)

Answer:

Step-by-step explanation:

1. the area of square is 9x^2-12x+4 square units

shortcut: (a-b)^2= a^2-2ab+b^2

then simplify 9x^2-12x+4 to (3x-2)^2

area of square = s^2

then side equals sqrt((3x-2)^2)

s = (3x-2) units

2. the area of rectangle is (25x^2-16y^2) square units

shortcut: (a^2-b^2) = (a-b)(a+b)

then simplify (25x^2-16y^2) to (5x-4y)(5x+4y) square units

one side is: (5x-4y) units

one side is (5x+4y) units

Combine like terms.

3p2q2-3p2q3+4p2q3-3p2q2+pq

Answers

Answer:

104

Step-by-step explanation:

:D

4) John's sister is 8 years less than twice his age. If John is 39, what age is his sister?

Answers

Answer:

Sister is 70

Step-by-step explanation:

John is 39.

8 less than twice his age is

39*2-8 = 70

Answer:

70 years old.

Step-by-step explanation:

Since John's sister is 8 years younger than TWICE his age, we just need to multiply 39*2 which equals 78. Now we just need to subtract 8 which equals 70.

Hope this helps!! <3

Jeff's sister drives 14 miles to her collage his brother only drives 5/7/10 miles to his collage how much farther does Jeff's sister drive than his brother

Answers

Answer:

8.3miles

Step-by-step explanation:

Here Jeff's sister drives 14 miles

his brother only drives 57/10 miles then the question is only asking the difference between their distance of driving to school knowing fully well that Jeff's sister drive farther than his brother, then we find the difference between their drives which is done bow

14miles -57/10 miles

= 83/10

= 8.3miles

Therefore, Jeff's sister drive 8.3miles farther than his brother

Determine the equation for the line of best fit to represent the data.

Answers

Answer:

Y= -1/5x + 1

Step-by-step explanation:

Just type it on a graphing calculator an click graph

HELP ASAP MONEY & WAGES!

Answers

Answer:  $26.70 per hour

Step-by-step explanation:

Regular hours consists of 8 hrs

Overtime hours is 12 - 8 = 4 hours

Regular pay at "x" per hour = 5(8)(x) = 40x

Overtime pay at "2x" per hour = 5(4)(2x) = 40x

                                                  Total pay = 80x

Total Pay = $2136 = 80x

                     [tex]\dfrac{\$2136}{80}=x[/tex]

                   $26.70 = x

WILL GIVE BRAINLEIST!!!!!

Find the surface area of the right triangular prism shown below.

Answers

Answer:

144 units²

Step-by-step explanation:

Surface area of a traingular prism is given as:

Area = 2(B.A) + P*L

Where,

B.A = base area of the triangular prism = ½*b*h

b = base of the triangular base = 4 units

h = height of the triangular base = 3 units

Base Area (B.A) = ½*4*3 = 2*3 = 6 units²

P = Perimeter of triangular face = sum of all sides the triangle = 3 + 4 + 5 = 12 units

L = length or height of prism = 11 units

Plug in all values into the formula for surface area of triangular prism = 2(B.A) + P*L

[tex] Area = 2(6) + 12*11 [/tex]

[tex] = 12 + 132 [/tex]

[tex] Surface Area = 144 [/tex]

Surface area of the triangular prism = 144 units²

Triangle TQRS Find the value of x.
O x = 2
O x = 3
O x= 33
O x= 52

Answers

Answer:

x=3

Step-by-step explanation:

To solve for x, we will follow the steps below:

First note that exterior angle =two  opposite interior angle

From the diagram below

(25x) ° + (57 + x)°   = (45x)°

25x° + 57° + x° = 45x°

next step is to collect the like term

45x° - 25 x°  - x°  =  57°

19x° = 57°

Divide both-side of the equation by 19

19x°/ 19 = 57° /19

On the left-hand side of the equation 19 will cancel out 19 leaving us with just x°  while on the right-hand side of the equation 57 will be divided by 19

x  =   3

Last week Lisa had a gross earning of $1441.30. Cathy receives a base salary of $375 and a commission on sales exceeding her quota of $5000. What is her rate of commission if her sales were $6560?

Answers

Answer:

4.25%

Step-by-step explanation:

Commision =  441.30 - 375 = 66.30

Commision is based on  = 6560-5000 = 1560

Rate of Commision = (in decimal) 66.30/1560 = 0.0425  

Rate of Commision = 0.0425  * 100 =   4.25 %

A tissue sample is three cells thick. Each cell has a thickness of 0.000004m. What is the thickness of the tissue sample in mm. Give your answer in standard form. PLZ SHOW WORKING NOT IN NANO METERS. IN STANDARD FORM

Answers

Answer:

0.012 millimeters

Step-by-step explanation:

First, we solve for  0.000004 m to mm = 0.004 mm x 3 = 0.012 millimeters

A rectangle has a height of 2 and a width of 5x^2-2x+3x

Express the area of the entire rectangle.
Expression should be expanded.

how would I do this?^^ if you can break down the steps for me that'd be amazing!​

Answers

Answer:

[tex] area = 10x^2 - 4x + 6 [/tex]

Step-by-step explanation:

Given that the rectangle has a height = 2, and width of [tex] 5x^2 - 2x + 3 [/tex]

Area of the whole rectangle can be calculated as:

[tex] area = 2(5x^2 - 2x + 3) [/tex]

Use the distributive property of multiplication by using 2 to multiply each term in the expression, [tex] (5x^2 - 2x + 3) [/tex]

[tex]area =2(5x^2) +2 (-2x) + 2(3)[/tex]

[tex] area = 10x^2 - 4x + 6 [/tex]

pleaseeeeeeeeee helllllllpppppp pleaseeeeee hellpppp​

Answers

Answer:

a. u = 19b. t = 6c. a = 2

Step-by-step explanation:

a. Given,

v = 34 , a = 5 , t = 3

[tex]v = u + at[/tex]

plugging the values:

[tex]34 = u + 5 \times 3[/tex]

Calculate the product

[tex]34 = u + 15[/tex]

Move 'u' to L.H.S and change its sign

[tex] - u + 34 = 15[/tex]

Move constant to RHS and change its sign

[tex] - u = 15 - 34[/tex]

Calculate

[tex] - u = - 19[/tex]

The difference sign (-) will be cancelled in both sides:

[tex]u = 19[/tex]

b. Given,

v = 50 , u = 20 , a = 5

[tex]v = u + at[/tex]

plugging the values

[tex]50 = 20 + 5 \times t[/tex]

[tex]50 = 20 + 5t[/tex]

Move 5t to L.H.S and change its sign.

Similarly, Move 50 to R.H.S and change its sign

[tex] - 5t = 20 - 50[/tex]

Calculate

[tex] - 5t = - 30[/tex]

The difference sign (-) will be cancelled in both sides

[tex]5t = 30[/tex]

Divide both sides of the equation by 5

[tex] \frac{5t}{5} = \frac{30}{5} [/tex]

Calculate

[tex]t = 6[/tex]

c. Given,

v = 22 , u = 8 , t = 7

[tex]v = u + at[/tex]

plugging the values

[tex]22 = 8 + a \times 7[/tex]

[tex]22 = 8 + 7a[/tex]

Move 7a to LHS and change its sign

Similarly, Move constant to R.H.S and change its sign

[tex] - 7a = 8 - 22[/tex]

Calculate

[tex] - 7a = - 14[/tex]

The difference sign (-) will be cancelled in both sides

[tex]7a = 14[/tex]

Divide both sides of the equation by 7

[tex] \frac{7a}{7} = \frac{14}{7} [/tex]

Calculate

[tex]a = 2[/tex]

Hope this helps...

Good luck on your assignment..

Given each set of vertices, determine whether PQRS is a rhombus, a rectangle, or a square. List all that apply. Explain your reasoning, P(-2, -3). Q(2, - 6). R(6. - 3). S(2, 1)

Answers

Answer:

Rectangle

Step-by-step explanation:

Given the coordinates P(-2, -3). Q(2, - 6). R(6. - 3). S(2, 1), to determine the type of shape the quadrilateral is, we need to find the measure of the sides. To get the measure of each sides, we will take the distance between the adjacent coordinates using the formula to formula for calculating the distance between two points as shown;

D = √(x₂-x₁)²-(y₂-y₁)²

For the side PQ with the coordinate P(-2, -3). Q(2, - 6)

PQ = √(2-(-2))²-(-6-(-3))²

PQ = √(2+2)²-(-6+3)²

PQ = √4²-(-3)²

PQ = √16-9

PQ = √7

For the side QR with the coordinate Q(2, - 6) and R(6, -3)

QR = √(6-2))²-(-3-(-6))²

QR = √(4)²-(3)²

QR = √16-9

QR = √7

For the side RS with the coordinate R(6. - 3) and S(2, 1)

RS = √(2-6)²-(1-(-3))²

RS = √(-4)²-(1+3)²

RS = √16-(4)²

RS = √16-16

RS = 0

For the side PS with the coordinate P(-2, -3) and S(2, 1)

PS = √(2-(-2))²-(1-(-3))²

PS = √(4)²-(1+3)²

PS = √16-(4)²

PS = √16-16

PS = 0

For the quadrilateral to be a rectangle, then two of its sides must be equal and parallel to each other. A rectangle is a plane shape that has two of its adjacent sides equal and parallel to each other. Since two of he sides are equal i.e RS = PS and PQ = QR then the quadrilateral PQRS is a rectangle. Both rhombus and square has all of its sides equal thereby making them wrong.

what is the product of (-a+3)(a+4)?

Answers

[tex](-a+3)(a+4)=-a^2-a+12[/tex].

Hope this helps.

Answer:

-a²-a+12

Step-by-step explanation:

-a²+3a-4a+12

-a²-a+12

Jane’s mobile phone plan charges $0.05 per minute at daytime rates before 8 p.m. and $0.03 per minute at nighttime rates after 8 p.m. A conference call costs 1.5 times the normal rate. Calculate the cost of a conference call lasting from 7 p.m. to 8:30 p.m.

Answers

Answer

5.85

Step-by-step explanation:

$0.05 x 1.5 = 0,075 x 1 hour (60) = 4,5

$0.03 x 1.5 = 0,045 x half an hour (30) = 1,35

So 4.5 + 1.35 = 5.85

Answer:

Step-by-step explanation:

Cost of the conference call before 8 pm =0.15 * 0.05 = $ 0.075

Cost of the conference call after 8 pm   = 0.15 * 0.03 = $ 0. 045

Cost of the conference call from 7pm to 8pm that last  60 minutes= 0.075 * 60

= $ 4.50

Cost of the conference call 8pm to 8:30pm =0.045 * 30 = $ 1.35

Cost of the conference call 7 pm to 8:30 pm = 4.50 + 1.35 = $ 5.85

Can someone pls help will mark u as brainliest

Answers

Answer:

9*((2-1)/9)

or

2 -1

9

2-9 =-7

9. 9

9× -7

9

=-7

2- 3

9. -3

=(1.22222222222)

or

11/9

or

1*(2/9)

N students joined the radio control club. Some had boats, some had airplanes, and some had cars. They divided into 3 equal groups according to what model each one had. Ten more students joined the radio-controlled airplane group. There are 15 students in this group now. How many students joined the radio control club in the beginning?

Answers

Answer:

36 people joined the radio control club.

Step-by-step explanation:

15-3= 12

12*3=36

PLEASE ANSWER ASPAA The x-intercept of the equation 2y – x = -6 is: 3. -3. 6. None of these choices are correct.

Answers

Answer:

x = 6

Step-by-step explanation:

The x-intercept of the equation is where the graph crosses the x-axis when y = 0. So, we simply plug in 0 for y:

2(0) - x = -6

0 - x = -6

-x = -6

x = 6

Alternatively, you can graph the equation into a graphing calc and analyze where the graph crosses the x-axis.

solve systems by substitution method x + y = 20 3x + 4y = 72

Answers

Answer:

x = 8; y = 12.

Step-by-step explanation:

x + y = 20

x = -y + 20

3x + 4y = 72

3(-y + 20) + 4y = 72

-3y + 60 + 4y = 72

y = 12

x + 12 = 20

x = 8

Check your work!

3(8) + 4(12) = 72

24 + 48 = 72

72 = 72

Hope this helps!

Answer:

X=-12 and Y= 32

Step-by-step explanation:

x+y=20 -> 1

3x+4y=72 -> 2

Form 1,

[x+y=20]×4

4x+4y=60 ->3

Form 2,

3x+4y=72

4y= 72 -3x ->4

Sub (4) into (3)

4x+72-3x= 60

x = -12

Sub X=-12 into (1)

-12+y=20

y= 32

Hope this helps.

If point Q is reflected across x = 1, what are the coordinates of its reflection image?

Answers

Answer:

(-1, -2) last answer

Step-by-step explanation:

x = 1 is a vertical line

Answer:

(-1, -2)

Step-by-step explanation:

This is because the x-coordinate goes 2 units left to the line x = 1 and the y-coordinate remains the same.

!!!!!!WILL GIVE BRAINLEIST !!!!!!

Answers

Answer:

[tex]\boxed{Median = 152}[/tex]

Step-by-step explanation:

Observation = 568 , 254 , 152 , 101 , 100

In ascending order:

=> 100 , 101 , 152 , 254 , 568

Median is the middlemost no. So here:

Median = 152

Answer:

152

Step-by-step explanation:

If you set the data in an ascending order, you will find 152 to be the middle value, thus being the median

A sphere has a diameter of 12 ft. What is the volume of the sphere? Give the exact value in terms of pi

Answers

Answer:

288π

Step-by-step explanation:

V=4 /3πr^3 is the formula. We have the diameter, so the radius is half (6). We now have V=4 /3π(6)^3 = 4/3π216 = 288π.

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Which glide reflection describes the mapping ABC DEF. This is practice for me plz, give answer with explanation. Non-sense answer will get reported Which of the following improves your range of motion and helps preventinjuries?A. Strong cardio-respiratory endurance.B. Strong flexibility.O c. A healthy bbyly composition.O D. A good sense of balance.SUBMIT Alice is building a caterpillar habitat for some caterpillars she found in her back yard. She plans to cover all sides of the habitat with screen so the caterpillars get plenty of fresh air. What is the total amount of screen that Alice will need for her habitat? Give an exact answer (do not round). 2) The senior classes at High School A and High School B planned separate trips to the localamusement park. The senior class at High School A rented and filled 2 vans and 14 buses with294 students. High School B rented and filled 3 vans and 7 buses with 161 students. Each vanand each bus carried the same number of students. Find the number of students in each van andin each bus.A) Van: 9, Bus: 28 B) Van: 11, Bus: 27C) Van: 20, Bus: 7 D) Van: 7, Bus: 20 These tables of values represent continuous functions. For which function will the y-values be the greatest for very large values of x? a 12- inch ruler is duvided into 3 parts. the large part is 3 times longer than the small. the meddium part is times longer than then small, the medium part is 2 times long as the smallest .how long is the smallest part? Use the quadratic formula to find the exact solutions of x2 5x 2 = 0. x equals negative b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a x equals 5 plus or minus the square root of 33, all over 2 x equals negative 5 plus or minus the square root of 33, all over 2 x equals 5 plus or minus the square root of 17, all over 2 x equals negative 5 plus or minus the square root of 17, all over 2 Which of the following allows the passage of small molecules between animal cells? Please choose the correct answer from the following choices, and then select the submit answer button. desmosomes nucleoli tight junctions black holes gap junctions Cause: Hitler took control of the economy. Effect: Unemployment among men . The equation of line l is -3y+4x=9 Write the equation of a line that is parallel to line l and passes through the point (-12,6). a) -3y+4x-69=0 b)-3y+4x-69=0 c)-3y+4x-39=0 d) 3x-3y+66=0 Which describes how to graph g (x) = RootIndex 3 StartRoot x minus 5 EndRoot + 7 by transforming the parent function? which of the following reaction would result in a decrease in entropy? Below are two chemical equations. One is for cellular respiration and one is for photosynthesis. Correctly place the reactants and products in the right location to complete both equations. Photosynthesis: H20 +H20------------->C6H12O6 +O2 +solar energy CO2 Cellular Respiration:O2+C6H1206 -------->CO2 + H2O +02 In which table does y vary inversely with x? A. x y 1 3 2 9 3 27 B. x y 1 -5 2 5 3 15 C. x y 1 18 2 9 3 6 D. x y 1 4 2 8 3 12 Read and choose the correct option to complete the sentence. Pablo, no sales con amigos y ests ________; visita a la terapeuta para recibir ayuda. activo contento saludable triste Please help. Ill mark you as brainliest if correct! An 1300-turn coil of wire that is 2.2 cmcm in diameter is in a magnetic field that drops from 0.14 TT to 0 TT in 9.0 msms . The axis of the coil is parallel to the field.What is the emf of the coil? (in V) Historically, the proportion of students entering a university who finished in 4 years or less was 63%. To test whether this proportion has decreased, 114 students were examined and 51% had finished in 4 years or less. To determine whether the proportion of students who finish in 4 year or less has statistically significantly decreased (at the 5% level of signficance), what is the critical value A car travels 133 mi averaging a certain speed. If the car had gone 30 mph faster, the trip would have taken 1 hr less. Find the car's average speed. reason for why english is a universal language