Leah earns 5x + 8y dollars, after x hours babysitting and y hours at the ice cream shop.
She wants to earn at least $120, then:
5x + 8y ≥ 120
Given that Leah babysits for 7 hours, then:
5(7) + 8y ≥ 120
35 + 8y ≥ 120
8y ≥ 120 - 35
8y ≥ 85
y ≥ 85/8
y ≥ 10.625
She must work at least 11 hours
Given that 7 + 11 = 18, then she would not work more than 20 hours as she expected
