5) The solution to 7X2 + 2X – 1 = 0 can be written as:

Answers

Answer 1

Answer:

2/7 or -30/7

Step-by-step explanation:

Use the quadratic formula

a = 7, b = 2, c = -1

-2 + or - (sqrt (2^2 - 4 * 7 * -1) / 2 * 7

-2 + or - 32/14

-2 + or -  16/7

2/7, or -30/7

Answer 2

Answer:

Step-by-step explanation:

7x² + 2x - 1 = 0

x = (-2 ±[tex]\sqrt{2^2 - 4(7)(-1)}[/tex] )/ (2(7))

x = (-2 ± [tex]\sqrt{32}[/tex] ) /14

x = (-2 ± 4[tex]\sqrt{2}[/tex] ) /14

x = [tex]\frac{-1}{7}[/tex] ± [tex]\frac{2}{7}[/tex][tex]\sqrt{2}[/tex]


Related Questions

Complete the table of ordered pairs for the linear equation

Answers

Answer:

Step-by-step explanation:

See attachment.

How to find domain of (1/x-3)(x^2-x-12)

Answers

Set denominator to zero and solve for x.

x^2 - x - 12 = 0

Factor.

(x - 4)(x + 3) = 0

Solve each factor for x.

x - 4 = 0

x = 4

x + 3 = 0

x = -3

Answer:

The domain is ALL REAL NUMBERS except for x = 4 and x = -3.

To make cupcakes Leah uses 1/2 cup of chocolate chips for evry 1 1/3 cups of batter if Leah uses 3/4 cups of chocolate chips how many cups of batter should she use

Answers

Answer:

2

Step-by-step explanation:

Leah uses 1/4 cup of chocolate chips for 2/3 cups of batter, so if Leah uses 3/4 cup of chocolate chips, she should use 2 cups of batter.

If [tex]a + ar + ar^{2} + ... = 15[/tex] and [tex]a + ar^{2} + ar^{4} + ar^{6} + ... = 9[/tex], then what is the sum of the geometric series [tex]a + ar^{3} + ar^{6} + ar^{9} + ...[/tex]?

Answers

Notice that

a + ar³ + ar⁶ + ar⁹ + ... = a + r³ (a + ar³ + ar⁶ + ...)

but the grouped sum on the right side is the same as the sum on the left side. This means that, if the sum we want to compute

a + ar³ + ar⁶ + ar⁹ + ...

converges to S, then

S = a + r³ S

Solve for S :

S - r³ S = a

(1 - r³) S = a

S = a/(1 - r³)

Similarly, knowing the value of the first sum, we have

a + ar + ar² + ar³ + ... = a + r (a + ar + ar² + ...)

but we know

a + ar + ar² + ... = 15

so

15 = a + 15r

and knowing the value of the second sum, we have

a + ar² + ar⁴ + ... = a + r² (a + ar² + ar⁴ + ...)

so

9 = a + 9r²

Solve these two equations for a and r :

15 = a + 15r   ⇒   a = 15 - 15r

9 = a + 9r²   ⇒   9 = 15 - 15r + 9r²   ⇒   3r² - 5r + 2 = (3r - 2) (r - 1) = 0

⇒   r = 2/3 or r = 1

We cannot have r = 1, since that would mean

a + a + a + ... = 15

since the left side is adding infinitely many copies of some constant; such a sum can never converge to a finite number. So it must be that r = 2/3, and it follows that a = 15 - 15 (2/3) = 5.

Then the sum we want has a value of

S = 5/(1 - (2/3))³ = 135/19

Answer:

Step-by-step explanation:

  a + ar¹ + ar² + ar³ + ... = 15       #1

r(a + ar¹ + ar² + ar³ + ...) = 15r

       ar¹ + ar² + ar³ + ... = 15r      #2

subtract #2 from #1

a = 15 - 15r

     a + ar² + ar⁴ + ar⁶ + ... = 9         #3

r²(a + ar² + ar⁴ + ar⁶ + ... )= 9r²

         ar² + ar⁴ + ar⁶ + ... = 9r²       #4

subtract #4 from #3

a = 9 - 9r²

15 - 15r = 9 - 9r²

9r² - 15r + 6 = 0

3r² - 5r + 2 = 0

r = (5 ±√(5² - 4(3)(2))) / (2(3)

r = (5 ± 1) / 6

r = 1

or

r = 4/6 = 2/3

if r = 1 then a = 15 - 15(1) = 0 and a series of zeros added together can never equal 15 so r = 2/3 must be true.

a = 15 - 15(2/3) = 5

   a + ar³ + ar⁶ + ar⁹ + ... = C           #5

r³(a + ar³ + ar⁶ + ar⁹ + ...) = Cr³

         ar³ + ar⁶ + ar⁹ + ... = Cr³          #6

subtract #6 from #5

a = C - Cr³

a = C(1 - r³)

C = a/(1 - r³)

C = 5/(1 - (2/3)³)

C = 5/(1 - 8/27)

C = 5/(19/27)

C = 5(27/19)

C = 135/19 = 7.1052631578947368....

A house costs 36% more today than when it was built.If the cost of the house today is $333,200, find the cost when it was built.​

Answers

Answer:

$245,000

Step-by-step explanation:

Let the intial cost = x

[tex]100\% + 36\% = 136\% = 1.36[/tex]

[tex]1.36x = 333200[/tex]

[tex]x = \frac{333200}{1.36} [/tex]

[tex]x = 245000[/tex]

y=5/9x+9, find the slope

Answers

the slope would be 4/9

What is 50 million + 32 hundred thousands + 41 hundred

Answers

Answer:

82041000

Step-by-step explanation:

50,000,000 + 32,000,000 + 41,000

Austin is running. The number of calories he has burned varies directly with the number of minutes he has run. See the graph below. 400 350+ 300 250 + Calories burned 200+ 150 100+ 50+ 0 20 10 30 80 Number of minutes

a) how many minutes does austin run per calories burned?

b) what is the slope of the graph?​

Answers

Answer:

223454353.000000000000000000

Step-by-step explanation:

A refrigeration system of 60 kW capacity at an evaporator temperature of – 40°C and a condenser temperature of 20°C is needed in a food storage locker. The refrigerant R134a is sub-cooled by 10°C before entering the expansion valve. The vapour is 0.98 dry as it leaves the evaporator coil. The compression in the compressor is of adiabatic type.

A 20 cm long thin wire is used to form a square. What is the area of the square?

Answers

Answer:

25cm^2

Step-by-step explanation:

A square has 4 equal sides so each side will be 20/4 = 5cm

Easily calculate the area by taking 5 x 5 = 25cm^2

In solving the following system of equations, how many equations do you need to multiply in order to use the method of elimination?

Equation 1: −5x−20y=−15 Equation 2: 2x + 8y = 6

A. Two
B. None
C. One

Give the solution to the system above
A. No solution
B. (3, 7)
C. IMS
D. ( -2, 5)

Answers

Answer:

a and d i think

Step-by-step explanation:

Which number line represents the number 0.7

Answers

Answer:

What number like?

Answer: The answer is C.

The question I assume you are talking about is in the image.

What are the odds of choosing a blue marble from a bag that contains two blue marbles, one green marble and four red marbles?

Answers

Answer:

1/3

Step-by-step explanation:

2 blue 1 green 4 red

2. Calculate an expression for dy/dx and d2y/dx2 in terms of t if the parametric pair is given as tan(x) = e^at and e^y = 1 + e^2at

Hint: Turn tan(x) = e^at and e^y = 1 + e^2at into expressions suited to your calculation.​

Answers

I assume a is a constant. If tan(x) = exp(at) (where exp(x) means eˣ), then differentiating both sides with respect to t gives

sec²(x) dx/dt = a exp(at)

Recall that

sec²(x) = 1 + tan²(x)

Then we have

(1 + tan²(x)) dx/dt = a exp(at)

(1 + exp(2at)) dx/dt = a exp(at)

dx/dt = a exp(at) / (1 + exp(2at))

If exp(y) = 1 + exp(2at), then differentiating with respect to t yields

exp(y) dy/dt = 2a exp(2at)

(1 + exp(2at)) dy/dt = 2a exp(2at)

dy/dt = 2a exp(2at) / (1 + exp(2at))

By the chain rule,

dy/dx = dy/dt • dt/dx = (dy/dt) / (dx/dt)

Then the first derivative is

dy/dx = (2a exp(2at) / (1 + exp(2at))) / (a exp(at) / (1 + exp(2at))

dy/dx = (2a exp(2at)) / (a exp(at))

dy/dx = 2 exp(at)

Since dy/dx is a function of t, if we differentiate dy/dx with respect to x, we have to use the chain rule again. Suppose we write

dy/dx = f(t)

By the chain rule, the derivative is

d²y/dx² = df/dx

d²y/dx² = df/dt • dt/dx

d²y/dx² = (df/dt) / (dx/dt)

d²y/dx² = 2a exp(at) / (a exp(at) / (1 + exp(2at)))

d²y/dx² = 2 (1 + exp(2at))

what is the equation for: 32 is the sum of a number x and 9

Answers

Answer:

x + 9 = 32

Step-by-step explanation:

answer for x is 32 - 9 = 23

What is the answer to the following question?

Answers

Answer:

  SAS similarity

Step-by-step explanation:

You have two side ratios and the angle between the sides with those ratios. The appropriate similarity theorem is SAS.

need help with this problem

Answers

Check the picture below.

Find the 57th term of the arithmetic sequence -13,-29,-47,….

Answers

Answer:

answer -909 photo with solution is attached

End of semester geometry Semester A question 6


Select the correct answer.
Given:

Prove:



By the linear pair theorem, is supplementary to . Since , by the definition of congruence, . Applying the substitution property of equality, . Simplifying the equation, .

What step is missing from this proof?

A.
is supplementary to by the transitive property.
B.
by the definition of supplementary angles.
C.
by the definition of congruence.
D.
by the linear pair theorem.

Answers

Answer:

by the definition of congruence.

Step-by-step explanation:

for plato

4. This diagram is a straightedge and compass construction of a line perpendicular to line AB passing through point C. Which segment has the same length as segment EA.

a. EC

b. ED

C. BE

d. BD​

Answers

Answer:

Segment ED has the same length as EA

The line segment which is equal to EA is ED. Therefore, option B is the correct answer.

In the given diagram, a line perpendicular to line AB passes through point C.

What is the tangent to the circle?

A tangent to a circle is a line which intersects the circle at only one point. The common point between the tangent and the circle is called the point of contact.

The length of two tangents drawn from an external point to a circle is equal.

From the given figure we can see there are three circles, two large circles and one small circle.

Line segment EA is tangent to a small circle.

The line segment which is equal to EA is ED because ED is another tangent to a small circle from the same external point.

The line segment which is equal to EA is ED. Therefore, option B is the correct answer.

To learn more about the tangent to a circle visit:

https://brainly.com/question/16592747.

#SPJ2

SOEMONE PLEASE TELL ME DID I CLICK THE RIGHT ONE
PLEASE PLEASE HELP ME

Answers

Answer:

Yes.

Step-by-step explanation:

I had a problem just like this and you are correct.

What is 1.8 added 8 times? (IF YOU CAN PLS DO IT IN EXPLANATION) and this is about decimals and pls do it in grade five type, bc I won't be able to understand anything too big for me, example: (e^(4^(2)
Thank you

Answers

Answer:

14.4

Step-by-step explanation:

1.8 added 8 times = 1.8 * 8

1.8 * 8

use distributive property

1.8 = 1 + 0.8

1.8 * 8 = (1+0.8) * 8

          = 1*8 + 0.8*8

anything multiplied by 1 equals itself

1*8 + 0.8*8 = 8 + 0.8 * 8

0.8 = 8/10

0.8 * 8 = (8/10) * 8

           = 64/10

            = 6.4

8 + 0.8 * 8 = 8 + 6.4 = 14.4 as our answer

A group of pigs and ducks has a total of 40 feet. There are twice as many ducks as pigs. How many of each animal are there?

Answers

The question relates to the total number of pairs of feet ducks and a pigs

are known to have.

There are 5 pigs and 10 ducks

Reasons:

The length of the group of ducks and pigs = 40 feet

Number of ducks = Twice the number of pigs

Each duck has 2 feet.Each pig has 4 feet.

Let x represent the number of pigs, and let y represent the number of ducks, we have;

y = 2 × x

4·x + 2·y = 40

Which gives;

4·x + 2 × (2·x) = 40

8·x = 40

x = 40 ÷ 8 = 5

The number of pigs, x = 5

y = 2 × x

Therefore;

y = 2 × 5 = 10

The number of ducks, y = 10

Learn more about solving word problems in mathematics here:

https://brainly.com/question/25272317

-6 • f(-3) - 5 • g(-7) =
please help

Answers

18f + 35g
Simplify each term.

Answer:

18f+35g

Step-by-step explanation:

Negative six times negative three will be equivalent to positive f, as negative negative five times negative seven equals thirty-five.

the two windows shown are similar. What is the height of the larger window?​

Answers

Answer:

The height of the larger window is 15.36 units.

Step-by-step explanation:

Let the height of the larger window be h.

The width and height of smaller window are 5 and 8 respectively.

The width and height of smaller window are 9.6 and h respectively.

It is given that both windows are similar. The corresponding sides of similar figures are proportional.

\frac{5}{9.6}=\frac{8}{h}

9.6

5

=

h

8

5h=8\times 9.65h=8×9.6

5h=76.85h=76.8

Divide both sides by 5.

h=\frac{76.8}{5}=15.36h=

5

76.8

=15.36

Therefore the height of the larger window is 15.36 units.

PLEASE HELP THIS WILL GIVE 50 POINT AND BRAINLIEST!!!!!!
In introductory physics, a typical cavendish balance for measuring the gravitational constant G use metal masses 2.39kg and 16g whose center are separated by 6.81cm calculate the gravitation force between these forces, treating each as a point mass located at the center of the sphere.

gravitational constant =6.67259 × 10⁻¹¹N·m²/kg²

Answers

Answer:

the asnswer is -67463 to the power of 4

Step-by-step explanation:

Pls help with these questions!

Answers

Answer:

I don't know sorry

Which number comes next in the series? 7, 10, 10, 13, 16, 16,

Answers

19 comes next in the series, followed by two 21s.

Answer:

19

Step-by-step explanation:

In the first number, they add three and that number is repeated.

To further explain, the series would continue like this:

7, 10, 10, 13, 16, 16, 19, 22, 22...

Hope this helps! Brainliest would be appreciated!

What is the eighth term of the arithmetic sequence defined by the rule A(n) = -12 + 2(n-1)?

Answers

Tn = a + d * (n-1)

T8 = -12 + 2*7

= -12 +14

= 2

someone please help me giving brainlist

Answers

Answer:

A

Step-by-step explanation:

which relation is a function?​ PLEASE HELPPPPP

Answers

Step-by-step explanation:

in the first

x =2y

actually I don't think that I can get the last two relations

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