The variable in -8y^4 is? Help needed.

An actor invests some money at 7%, and $24000 more than four times the amount at 8%. The total annual interest earned from the i

natita [175]

Answer:

$70,000 at 7%
$304,000 at 8%

Step-by-step explanation:

Given:

Total interest earned on two investments is $29,220.

An amount is invested at 7%.

$24,000 more than 4 times that amount is invested at 8%.

Find:

The amount invested at each rate.

Solution:

Our strategy will be to define a variable representing the amount invested at 7%, use that variable to write an expression for the amount invested at 8%, then write an equation for the total return on the investments.

Let x represent the amount invested at 7%. Then (24,000+4x) will be the amount invested at 8%. The total interest earned will be ...

interest on 7% account + interest on 8% account = total interest

0.07x + 0.08(24000+4x) = 29220

0.39x + 1920 = 29220 . . . . . . . . . . . simplify

0.39x = 27300 . . . . . . . . . . . . . . . . . .subtract 1920

x = 27300/0.39 = 70000 . . . . . . . . . divide by the coefficient of x

24,000 +4x = 24,000 +280,000 = 304,000 . . . . amount invested at 8%

He invested $70,000 at 7% and $304,000 at 8%.

Check

The answer must satisfy ...

7% interest + 8% interest = 29,220

0.07×70,000 +0.08×304,000 = 4,900 +24,320 = 29,220 . . . . as required

_____

Comment on 6-step method

We have tried to hit the highlights. Your steps appear to be ...

Identify the given information (Given)
Identify the question you are asked to answer (Find)
Identify the useless information in the problem statement (is none)
Decide on a strategy. Make a model or drawing. (model equation shown)
Solve and show work (Solution)
Explain why the answer makes sense (Check)

6 0

3 years ago

Which of the following is an example of the Distributive Property?

In-s [12.5K]

Answer:

2z2(2y - 5) = 4z2y - 10z2

Step-by-step explanation:

I hope this helps

8 0

3 years ago

Read 2 more answers

Use the given inverse to solve the system of equations. left brace Start 3 By 3 Matrix 1st Row 1st Column x minus y plus z 2nd C

natka813 [3]

The interpretation of the given question is as follows:

Use the given inverse to solve the system of equations

$x- y - z = -6 \\ \\ 2y + z = -6 \\ \\ 3x -8 y = - \dfrac{1}{2}$

The inverse of $\left[\begin{array}{ccc}1&-1&1\\0&2&1\\3&-8&0\end{array}\right] is \left[\begin{array}{ccc}-8&8&3\\-3&3&1\\6&-5&-2\end{array}\right]$

x =

y =

z =

Answer:

x = - 1.5

y = - 0.5

z = - 5

Step-by-step explanation:

Using the correlation of inverse of matrix AX = B to solve the question above;

AX = B

⇒ A⁻¹(AX) = A⁻¹ B

X = A⁻¹ B

So ;

X = A⁻¹ B

$\left[\begin{array}{c}x\\y\\z\end{array}\right] =$ $\left[\begin{array}{ccc}-8&8&3\\-3&3&1\\6&-5&-2\end{array}\right] =$ $\left[\begin{array}{ccc}-6\\ -6\\- \dfrac{1}{2}\end{array}\right]$

$\left[\begin{array}{c}x\\y\\z\end{array}\right] =\left[\begin{array}{ccc}(-8*-6)+(8*-6)+(3*-\dfrac{1}{2})\\(-3*-6)+(3*-6)+(1*-\dfrac{1}{2})\\(6*-6)+(5*-6)+(-2* - \dfrac{1}{2})\end{array}\right]$

$\left[\begin{array}{c}x\\y\\z\end{array}\right] =\left[\begin{array}{ccc}(48)+(-48)+(\dfrac{-3}{2})\\(18)+(-18)+(\dfrac{-1}{2})\\(-36)+(30)+(1)\end{array}\right]$

$\left[\begin{array}{c}x\\y\\z\end{array}\right] =\left[\begin{array}{ccc}(\dfrac{-3}{2})\\(\dfrac{-1}{2})\\(-5)\end{array}\right]$

$\left[\begin{array}{c}x\\y\\z\end{array}\right] =\left[\begin{array}{ccc}-1.5\\-0.5\\ -5\end{array}\right]$

5 0

3 years ago

PLEASE HELP!!!! 20 points

Vladimir79 [104]

Answer:

Interval notation [-2, 0) U (0, 7]

Step-by-step explanation:

4 0

3 years ago

Which of the following graphs best represents the solution to the pair of equations below? y = −x + 6 y = 2x − 3 A coordinate pl

Lera25 [3.4K]

The lines are

i) y=-x+6
ii) y=2x-3

The solution of the system of equations is found by equalizing the 2 equations:

-x+6=2x-3

-2x-x=-6-3

-3x=-9

x=-9/(-3)=3

substitute x=3 in either i) or ii):

i) y=-3+6=3
ii) y=2(3)-3=6-3=3

(the result is the same, so checking one is enough)

This means that the point (3, 3) is a point which is in both lines, so a solution to the system.

In graphs, this means that the lines intersect at (3, 3) ONLY

Answer: The graph where the lines intersect at (3, 3)

3 0

4 years ago