interest paid on the initial principal and on interest earned in the past

Karla invested $1,000 in savings bonds. If the bonds earn 6.75% interest compounded semi-annually, how much total will Karla earn in 15 years?

Emily would like to buy some new furniture for her home. She decides to buy the furniture on credit with 9.5% interest compounded quarterly. If she spent $7,400, how much total will she have paid after 8 years.

Jay'den earned $475 from mowing lawns last summer. He deposited this money in an account that pays an interest rate of 3.8% compounded annually.

What will be his balance after 15 year?

Ash has $8,000 in a savings account. The interest rate is 3% compounded semi-annually .

To the nearest cent, how much will he have in his account in 4 years?

Benjamin uses the equation $$P=1000\left(1+0.4\right)^t$$ to represent the amount of money in his bank account after t years. Determine what each part of the equation represents.

Ash has $8,000 in a savings account. The interest rate is 3% compounded once a year.

To the nearest cent, how much will he have in his account in 4 years?

Write an expression that would calculate the amount of money you would have after x years if you invested $3200 at a 12% interest rate that compounds every other month.

Which of the following exponential equations is the formula for compound interest?