The fourth term of a geometric progression is 4 and the seventh term is 32/125. Find the first term, the common ratio and the sum of the first nth terms. Hence, deduce the sum to infinity.​

Answers

Answer 1

Answer:

common ratio is 2/5

First term is  125/2

The sum of the first n terms is: [tex]S_n=\frac{125}{2} \, \frac{1-(2/5)^n}{3/5}[/tex]

The infinite sum is: [tex]S_\infty =\frac{625}{6}[/tex]

Step-by-step explanation:

The 4th term is 4, and the seventh term is 32/125 so we use the definition of nth term of a geometric sequence to create the following two equations:

[tex]a_4=a_1\,*\,r^{4-1} = a_1\,*\,r^3\\4=a_1\,*\,r^3\\and\\a_7=a_1\,*\,r^{7-1} = a_1\,*\,r^6\\\frac{32}{125} = a_1\,*\,r^6[/tex]

Now we divide a7 by a4 to get rid of a1 and work on determining the common ratio of the sequence:

[tex]\frac{a_7}{a_4} =\frac{8}{125} =\frac{a_1\,r^6}{a_1\,r^3} =r^3\\then\\r=\sqrt[3]{\frac{8}{125} } =\frac{2}{5}[/tex]

So, the common ratio is 2/5

we can now determine the first term:

[tex]a_4=4=a_1\,*\,(2/5)^3\\a_1=\frac{125*4}{8} =\frac{125}{2}[/tex]

The sum of the first n terms is given by the formula:

[tex]S_n=\frac{125}{2} \, \frac{1-(2/5)^n}{1-(2/5)} \\S_n=\frac{125}{2} \, \frac{1-(2/5)^n}{3/5}[/tex]

and therefore, the infinite sum is:

[tex]S_\infty = a_1\,\frac{1}{1-r} = \frac{125}{2} \,\frac{5}{3} =\frac{625}{6}[/tex]


Related Questions

Solve for n: n/3 > 66 2/3

Answers

Answer: The 2 answers are inequality form and interval notation: n>200, and (200, ∞).

Step-by-step explanation: To solve for n, you’ll need to simplify the both sides of the inequality, and then isolating the variable.

Completing the Square
Solve each equation by completing the square.
1) 7x2 + 14x - 65--9

Answers

Answer:

2(30-7x)

Step-by-step explanation:

=14+14x-65-9

=14+14x-79

=60+14x

=2(30-7x)

aye i have a code karen someone help please

go to this question on my page and then go to the first answer and there's a Karen in the comments
"1. what do you do to check weather a number is rational or irrational? in your explanation, use an example of irrational and a rational number. 2. how does finding the square root of a number compare to finding the cube root of a number? use the number 64 in your explanation. REALLY HIGH BRAINIRLY"

Answers

Answer:

1. If you're taking square roots, the number must be a perfect square to give a rational root.

64 = 8^2, so √64 = 8 is rational

Similarly, since

64 = 4^3, ∛64 = 4 is rational.

For small numbers, it's easy to check for possible roots, as there aren't that many candidates. In general, it's much more difficult.

2.

Step-by-step explanation:


What is the x-intercept of
3x – 4y = 242

Answers

Answer:

x=242/3

alternative form= 80 2/3, x=80.6

Step-by-step explanation:

3x-4y=242

substitute y = 0

3x-4x0=242

calculate the product

3x-0=242

remove 0

3x=242

divide both sides (by 3 in order to leave x by itself)

done

Sofia used these steps to find the inverse of function f

She made a mistake in step__(2,6,4,3,5)?

She should have_____
.dived each side by 8 instead of multiplying
.replaced x with f(x)
.divided each side by 3 instead of multiplying
.added 4 to each side instead of subtract
.restricted the domain to x>0

Answers

Answer:

Step-by-step explanation:

Step 1             f(x) = [tex]\frac{3x+4}{8}[/tex]                 Given

Step 2            y = [tex]\frac{3x+4}{8}[/tex]                    Change f(x) to y

Step 3            x = [tex]\frac{3y+4}{8}[/tex]                    Switch x and y

Step 4            8x = 3y + 4              multiply each side by 8

Step 5            8x - 4 = 3y               Subtract 4 from each side

Step 6            [tex]\frac{8x-4}{3}=y[/tex]                   Divide by 3 on each side

Step 7            [tex]\frac{8x-4}{3}=f^{-1}(x)[/tex]           Replace y by [tex]f^{-1}(x)[/tex]

Therefore, inverse of the function will be,

[tex]\frac{8x-4}{3}=f^{-1}(x)[/tex]

Sofia made a mistake in step 6. She should have divided both the sides by 3 instead of multiplying each side by 3.

Sophia has made mistake in step 6. She should have divided each side by 3 instead of multiplying.

The given function is [tex]f(x)=\dfrac{3x+4}{8}[/tex].

It is required to calculate the inverse of the function.

So, the steps involved in finding the inverse of the function will be,

Step 1:

Write the given function as,

[tex]f(x)=\dfrac{3x+4}{8}[/tex]

Step 2:

Change the function f(x) to y as,

[tex]y=\dfrac{3x+4}{8}[/tex]

Step 3:

Switch x and y as,

[tex]x=\dfrac{3y+4}{8}[/tex]

Step 4:

Multiply each side of the equation by 8 as,

[tex]8x=8\dfrac{3y+4}{8}\\8x=3y+4[/tex]

Step 5:

Now, subtract 4 from each side of the equation as,

[tex]8x-4=3y+4-4\\8x-4=3y[/tex]

Step 6:

Now, it is required to divide each side by 3.

[tex]\dfrac{8x-4}{3}=\dfrac{3y}{3}\\\dfrac{8x-4}{3}=y[/tex]

Step 7:

Now, replace y with [tex]f^{-1}(x)[/tex] as,

[tex]\dfrac{8x-4}{3}=f^{-1}(x)[/tex]

So, the required inverse function should be [tex]f^{-1}(x)=\dfrac{8x-4}{3}[/tex].

Therefore, Sophia has made mistake in step 6. She should have divided each side by 3 instead of multiplying.

For more details, refer to the link:

https://brainly.com/question/19606498

Simplify the expression using the properties of operations.
The simplified form of the expression (5.23x + 3.76) − (3.67x − 6.39) is

Answers

Answer:

Step-by-step explanation:

5.23x+3.76-3.67x+6.39

x(5.23-3.67) +(3.76+6.39)

1.56x + 10.15

Answer:

1.56x + 10.15

Step-by-step explanation:

(5.23x + 3.76) – (3.67x – 6.39)

(a + b) – (c – d) = a + b – c + d

Remove the parentheses and change the signs as needed:

5.23x + 3.76 – 3.67x + 6.39.

Group the like terms and simplify:

5.23x – 3.67x + 3.76 + 6.39

1.56x +10.15.

Which is equivalent to −2/5

Answers

Answer:

-0.4

Step-by-step explanation:

-2 divided by 5

Answer:

-4/10

Step-by-step explanation:

There are many more this is one of them.

if you ran 4 miles in 36 minutes how many minutes would you have to run in one mile?Explain

Answers

Answer:

9 minutes

Step-by-step explanation:

The length of a rectangle is four times its width.
If the perimeter of the rectangle is 90 yd, find its length and width.

Answers

Answer:

Length of rectangle = 36 yd and width of rectangle = 9 yd

Step-by-step explanation:

Let width of rectangle = w

Length of rectangle = 4w (four times the width)

Perimeter of rectangle = 90 yd

We need to find length and width of rectangle.

The formula used will be: [tex]Perimeter \ of \ rectangle=2(l+w)[/tex]

Where l is length and w is width

Putting values and finding length and width of rectangle

[tex]Perimeter \ of \ rectangle=2(l+w)\\90=2(4w+w)\\90=2(5w)\\90=10w\\w=\frac{90}{10}\\w=9[/tex]

So,width (w) of rectangle is w= 9 yd

Finding length of rectangle = 4w = 4*9 = 36 yd

So, length of rectangle = 36 yd and width of rectangle = 9 yd

What is the perimeter of this square?
aaaaaaaaaaaaaa
11 in

Answers

Answer:

44 in

Step-by-step explanation:

Perimeter is adding up all the sides together and since we know it is a square that means each side is equal

11 in + 11 in + 11 in + 11 in = 44 in

The two triangles are similar, What is the length of DE?

Answers

Answer:

If an angle of one triangle is congruent to the corresponding angle of another triangle and the lengths of the sides including these angles are in proportion, the triangles are similar. The corresponding sides of similar triangles are in proportion.

I hope this might help you

Mark it as brainliest answer and follow me

Write an equation of a line perpendicular to line CD in slope-intercept form that passes through the point (−1, 6).

Line CD is shown. C is at 1, 1. D is at 3, 5.

y = −0.5x − 5.5
y = −0.5x + 5.5
y = 2x + 13
y = 2x − 13

Answers

Answer:

its b

Step-by-step explanation:

i took the test

y = - 0.5x + 5.5 is the equation of a line perpendicular to line CD in slope-intercept form that passes through the point (−1, 6).

What is the slope-intercept form of a straight line?

The slope-intercept form of a straight line is y = mx + c.

Here, x and y are coordinates, m is the slope and c is the y-intercept of the line.

Given, two points are C(1, 1) and (3, 5).

Therefore, equation of the line CD is:

[tex]\frac{x - x_{1} }{y-y_{1} }[/tex] = [tex]\frac{x_{1}-x_{2}}{y_{1}-y_{2}}[/tex]

⇒ [tex]\frac{x - 1}{y-1}[/tex] = [tex]\frac{1-3}{1-5}}[/tex]

⇒  [tex]\frac{x - 1}{y-1}[/tex] = [tex]\frac{-2}{-4}}[/tex]

⇒2(x - 1) = (y - 1)

⇒ y = 2x - 1

Let, line AB is perpendicular to the line CD and passes through the point (-1, 6).

Therefore, slope of the line CD is = 2.

We know, slope of CD × slope of AB = -1

Therefore, slope of AB = -1 / slope of CD = [tex]-\frac{1}{2}[/tex].

Now, line AB has a slope of [tex]-\frac{1}{2}[/tex] and passes through the point (-1, 6).

Therefore, equation of the line AB is:

(y - y₁) = m(x - x₁)

⇒ [y - (6)] = [tex]-\frac{1}{2}[/tex][x - (- 1)]

⇒ 2(y - 6) = (-x - 1)

⇒ 2y - 12 + x + 1 = 0

⇒ x + 2y = 11

⇒ y = - 0.5x + 5.5

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what is the solution to this equation: 7m to the 2 power + 6m - 1 = ?

Answers

Answer:

7m² + 6m - 1

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Algebra I

Combining Like TermsStandard Form: ax² + bx + c = 0

Step-by-step explanation:

Step 1: Define expression

7m² + 6m - 1

Step 2: Simplify

The expression cannot be simplified further.

Find the value of r.

Answers

Answer:

r=0

Step-by-step explanation:

the line passes through the origin which means there is no y-intercept

What is the first step in solving for z in the equation
5z−4=26?

Answers

Answer:

Step-by-step explanation:

This is the completed answer.

5z - 4 = 26

5z−4+4=26+4

5z=30

Divide both sides by 5.

5z/5 = 30/5

z=6

Simplify (6x ^ 2 + 11x - 3) + (2x ^ 2 - 17x - 4) . (1 point)
1 ) 8x ^ 2 + 6x - 1
2) 8x ^ 2 - 6x - 7
3 ) 8x ^ 2 + 6x + 1
4 ) 8x ^ 2 - 6x + 7

Answers

Answer:

2) 8x^2 -6x-7 hope this helps

Penny reads 13 pages in 1/2 hour. What is the unit rate for pages per hour? For hours per page? How many hours per page

Answers

Answer:

13 pages : 1/2 hour Multiply both sides by 2

26 pages : 1 hour ------>> 26 pages/hr

Flip over 26 pages/hr ----->>> hr / 26 pages = 1 hr / 26 pages

Split up the fraction: (1/26) hr / page

Answer:

26

Step-by-step explanation:

13 in 1/2 hour

13:1/2

26:1

Is that a perfect square

Answers

Answer:

im gonna go with yes

Step-by-step explanation:

Answer:

is what a perfect square?

Step-by-step explanation:

there is no pic attached

Select the correct answer.
which equation represents the line that is parallel to y= 3 and passes through (-2,-8)?
А.
x = -2
B.
x=3
C. y=-8
D.y= 3x - 2

Answers

Answer: -8

Step-by-step explanation:

other people got -8 so I'm pretty sure this is the answer.

Use interval notation to express the set of real numbers $x$ that satisfies the inequality $-2 \leq x < 5$.

Answers

Answer:

[-2, 5)

Step-by-Step Explanation:

The solution set of the given inequality {x ;-2 ≤ x < 5} will be; [-2, 5).          

What is inequality?

Inequality is defined as the relation which makes a non-equal comparison between two given functions.

Given that the inequality y = {x ; -2 ≤ x < 5}

WE are asked to find the solution set for the given inequality;

⇒ y={x ; -2 ≤ x < 5} i.e domain= [-2, 5)

⇒y=x ∀ x ∈ [-2, 5)

The solution of the given inequality;

x ∈ [-2, 5)

Therefore, The solution set of the given inequality {x ;-2 ≤ x < 5} will be; [-2, 5).          

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Determine if the following argument always applies, sometimes applies, or never applies. Provide at least 2 examples in your explanation.

"The sum of a number and its opposite is always 1."

Answers

Answer:

Never applies

Step-by-step explanation:

Given

Argument: The sum of a number and its opposite is always 1

Assume a positive number x

The opposite of the number is negative x (i.e. -x)

The sum of both numbers is:

[tex]Sum = x + (-x)[/tex]

Open Bracket

[tex]Sum = x -x[/tex]

[tex]Sum = 0[/tex]

Now, take for instance.

[tex]Number = 5[/tex]

Opposite would be

[tex]Opposite = -5[/tex]

Their sum is:

[tex]Sum = 5 + (-5)[/tex]

[tex]Sum = 5 -5[/tex]

[tex]Sum = 0[/tex]

Another instance is:

[tex]Number = -8[/tex]

Opposite would be

[tex]Opposite = 8[/tex]

Their sum is;

[tex]Sum = -8 + 8[/tex]

[tex]Sum = -0[/tex]

Hence, the argument never applies because the sum is never 1

what number is represented by this number discs​

Answers

Answer:

15

Step-by-step explanation:

Which man made object is likely to endure long after humans have disappeared from New York city?

A. Ceilings

B. Sewer systems

C. Steel l-beams

D. Bronze sculptures ​

Answers

D. Bronze sculptures

Bronze sculptures ​endure long after humans have disappeared from New York city.

What is Man made objects?

Human-made materials are those that humans have manufactured. Such examples are rubber, paper, plastic, furniture, and clothing. Artificial satellites are man-made. They take off from the Earth.

As, Bronze is an extremely robust substance that can withstand many circumstances that softer metals cannot.

Utilizing this metal for art pieces is fantastic because it requires no maintenance and upkeep and can survive for hundreds of years, enhancing its worth even further.

Also, Bronze is last long than Steel.

Thus, Bronze sculptures ​endure long after humans have disappeared from New York city.

Learn more about Man made objects here:

https://brainly.com/question/14463482

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Can someone help me with this.. It is timed I WILL MARK YOU AS BRAINLIEST

Answers

(2p+13)(p−3)/2p-7
​​

Answer:

1) dividend

2) divisor

3) quotient

Would you please help me on this question?

Answers

Answer:

x = 2

Step-by-step explanation:

Given that the measure of segment BC must equal the addition of the measure of segment BA plus the measure of segment AC, we can write this in equation form:

BC = BA + AC

then we replace them with the measure information they provide:

12 x + 4 = 7 x - 4 + 8 x + 2

and we solve for x in the equation:

12 x + 4 = 15 x - 2

subtract 12 x from both sides:

4 = 15 x - 12 x - 2

4 = 3 x - 2

add 2 on both sides

4 + 2 = 3 x

6 = 3 x

x = 6/3

x = 2

How many more miles is 27.2 than 6.8

Answers

Answer:

20.4 miles

Step-by-step explanation:

Answer: 20.4

Step-by-step explanation: How many more miles is 27.2 than 6.8

usually these kind of equations mean to subtract, in other terms find the underlined key words

27.2-6.8= 20.4

What is the graph of the function rule?
1. y= 3x - 2 (1 point)
Algebra 1

Answers

This should be what you're looking for.

Solve the equation 3(x + 4.5) = 36.

If you get stuck, use the diagram. first one and with an explanation will get brainllest

Answers

Answer:

.75

Step-by-step explanation:

there is prof

Hint : Add togheter and =180​

Answers

Answer:

100 + 80

Step-by-step explanation:

What is the equation for the line in slope-intercept form?

Answers

Answer:

y=mx+b is slope-intercept form

where m is the slope and b is the y intercept.

Since the line crosses the y axis at 0,0 the intercept is +0 or just nothing.

now all we need to do is find the slope

to do that just go from the y intercept (the first point) y units up and x units over untill u cross at the next point. for examples from (0, 0) to (1, 8)-the next point- i need to go up 8 units up and 1 unit over. this is described as rise over run and that is your slope 8/1 rise/run. rise is how many units i go up (or down) from the y intercept until the next point that lies on the line and run is how far i need to go over from how many units i just went up. If u continue to go 8 up and 1 over from each point u will see that u get a point lying of the line. This is why 8/1 is your slope

8/1 is the slope and 0,0 is your y intercept so we put nothing

the equation is y=8x

Step-by-step explanation:

Answer:

y=8x

Step-by-step explanation:

Pick two points (0,0) (2,16)

Then 16-0/2-0= 8

8 is the slope

The y intercept is 0 so

y=8x

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