Helen borrowed $8,000 from her grandfather to pay for college. five years later, she paid him back the $8,000 and an interest of $1,200 . what was the annual interest rate?

3%.

Step-by-step explanation:

We have been given that Helen borrowed $8,000 from her grandfather to pay for college. Five years later, she paid him back the $8,000 and an interest of $1,200.

We will use following formula to find the annual interest rate.

, where,

,

,

,

.

Upon substituting our given values in above formula we will get,

Upon dividing both sides of our equation by 40,000 we will get,

Since our interest rate is in decimal form,let us convert it in percentage by multiplying 0.03 by 100.

Therefore, the annual interest rate was 3%.

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10

360/29

step-by-step explanation: