Answer:
Claire must work 4 hours cleaning tables and 5 hours washing cars to earn more than $ 90.
Since Claire is working two summer jobs, making $ 7 per hour washing cars and making $ 15 per hour clearing tables, and in a given week, she can work at most 9 total hours and must earn a minimum of $ 90, to determine one possible solution the following calculation must be performed:
15 x 9 = 135
135 - 90 = 45
45/7 = 6.42
6 x 7 + 3 x 15 = 42 + 45 = 87
5 x 7 + 4 x 15 = 35 + 60 = 95
Therefore, at a minimum, Claire must work 4 hours cleaning tables and 5 hours washing cars to earn more than $ 90.