Question

9. Luna opened an account with $50 and plans

to deposit $ 15 each week. On the same day,Mason opened an account with $10 and plans to deposit $25 each week. Write and solve an
inequality to represent the number of weeks
that Luna's account balance will be greater
than or equal to Mason's.

Answer 1

Explanation:

Let the number of weeks = x

Luna's account:

Amount deposited in x week = 15 *x = 15x

Balance after 'x' weeks = 50 + 15x

Mason's account:

Amount deposited in x weeks = 25 * x = 25x

Balance after 'x' weeks = 10 + 25x

Luna's account ≥ Mason's account

50 + 15x ≥ 10 + 25x

Subtract 10from both sides

50 - 10 + 15x ≥ 10 - 10 + 25x

40 + 15x ≥ 25x

Subtract 15x form both sides

40 ≥ 25x - 15x

40 ≥ 10x

Divide both sides by 10

40/10 ≥ x

4 ≥ x

x ≤4 weeks