Question

After earning interest, the balance of an account is $420. The new balance is 7/6 of the original balance.

Write an equation that can be used to find the original balance b of the account.

420=____

What was the original balance of the account?

$__

How much interest did the account earn?

$__

Answer 1

Equation: 420 = 7/6b, Original balance: $360, Interest earned: $60.

Explanation:

Since 420 is 7/6 of the original balance, and of means mulitply, we can make this into an equation, the equation is 420 = 7/6b. Let's solve the equation for b. Multiply both sides by 6 to get 2520 = 7b. Now, let's divide both sides by 7. This gets us 360 = b. This means the original balance was $360. Now, let's find the interest earned. We know that 420 is 7/6 of 360, so that means the interest earned was 1/6 of the original balance. Let's make sure, first. 360/6 is 60, and 360+60 is 420, so everything checks out.