Answer :
The value of number of hours overtime per week will he needed to achieve his earning goal = 5 hours
Explanation:
Payment for first 40 hours = $ 32 per hour
Payment over 40 hours = $ 48 per hour
Eli’s goal is to earn = $ 1520 per week ------- (1)
Total payment for first 40 hours = 32 × 40 = $ 1280 ------ (2)
Suppose person worked 
 hours in overtime, then
The total payment for 
 hours = 48 × 
 = $ 48
 ------------ (3)
Total earnings of the person in a week ⇒ $ 1280 + $ 48
 = $ 1520
⇒ 1280 + 48
 = 1520
⇒ 48
 = 1520 - 1280
⇒ 48
 = 240
⇒ 
 = 5 hours
This is the value of number of hours overtime per week will he needed to achieve his earning goal.