Question

9. A college savings account makes $75 ayear in interest. After four years, theaccount has $850.A. Write an equation to represent the amountof money in the account, y, after x years.b. How mush money will be in the account after ten years

Answer 1

A) Given that the savings account makes $75 a year in interest, then after x years, the account makes 75x dollars in interest.

The amount of money in the account, y, is the addition of the initial amount, I, and the amount made in interest, that is,

y = 75x + I

Substituting with y = $850, and x = 4 years, and solving for I, we get:

850 = 75*4 + I

850 = 300 + I

850 - 300 = I

550 = I

And the equation is:

y = 75x + 550

B) Substituting with x = 10 into the above equation:

y = 75*10 + 550

y = 750 + 550

y = 1300

There will be $1300 in the account after 10 years