Mike's grandmother opened a savings account in Mike's name and deposited some money into the account. The account pays an annual simple interest rate of 9%. After 12 years, the interest earned on the account was $8,640. How much money did Mike's grandmother deposit in the account? A.
$7,000
B.
$8,500
C.
$9,000
D.
$8,000

In this question we have to use the formula of simple interest, which is

I = P r t

Where I is the interest earned, P is the amount invested, r is the rate of interest and t is the time duration .

In the given question, I = $4840 , r =11% or 0.11, t=11, P is unknown .

Substituting the values in the formula, we will get

P=4000

So she invested $4000.

Step-by-step explanation:

hi there!

the answer will be d: 2

u = -(6/7)w

step-by-step explanation:

place all values with 'u' on one side of the equation.

4u + 8w = - 3u + 2w

4u + 3u = 2w - 8w

further simplify the equation by solving the addition and subtraction.

7u = - 6w

make 'u' the independent variable by placing its co-efficient on the right-hand side.

u = - (6/7)w