Sam has $400 in his bank account and plans to save $25 per week. Zoe has $250 in her bank account and plans to save $75 per week. How many weeks will it be before their accounts are equal?

Say x is the number of weeks until their money is equal. Then, we can set up an equation.

400 + 25x = 250 + 75x

Subtract 250 from both sides

150 + 25x = 75x

Subtract 25x from both sides

150 = 50x

Divide by 50 on both sides

3 = x

That means the answer is 3 weeks.