MODELING WITH MATHEMATICS

Question

Write and solve an equation to determine what the balance $b$b​  in the account was 4 years ago.

The balance of an investment account is $308 more than the balance 4 years ago. The current balance of the account is $4708.

Equation:  $=4708$=4708​

The balance of the account 4 years ago was $.

Answer 1

Hello, David,

I rewrote your question since I didn't understand what "$b$b" meant:

Write and solve an equation to determine what the balance in the account was 4 years ago.

Take each statement and rewrite the meaning as an equation. A₀ is the initial investment account balance, and A₄ is the account balance at 4 years.

The balance of an investment account is $308 more than the balance 4 years ago.

A₄ = A₀ + $308

This can also be written as A₀ = A₄ - $308

The current balance of the account is $4708. (I assume "current" means year 4.)

A₄ = $4708

The balance of the account 4 years ago was $.

Use the equation above and enter $4708 for A₄.

A₀ = $4708 - $308

A₀ = $4400

I hope this helps,

Bob

Answer 2

Interest=fv=p(1+int/c)^(cn)

future value

principal

int

compound

yrs

4708-308=4400

fv=4400(1+int/1)^(4)

int=17%

4 yrs ago bal was $4400.