Answer:
8.33≈ 9 hours.
Explanation:
She has $45 and she earns $9 per hour. So, the equation is y = 45+9x where y is the price of the ipod and x is the number of hours she need. Now,
120 = 45 + 9x
120 - 45 = 9x
75 = 9x
x = 75/9
x = 8.33.
Then, she need to work 8.33≈ 9 hours more to earn the rest of purchase.