Answer:
4 months and 7 months
Explanation:
C = 30x + 50
C is cost so when we spend $170 we can solve for x.
$170 = 30x + 50
170 - 50 = 30x + 50 - 50
170 - 50 = 30x
120 = 30x
120/30 = 30x/30
120/30 = x
4 = x
So he has played 4 months when he spends $170
C is cost so when we spend $260 we can solve for x.
$260 = 30x + 50
260 - 50 = 30x + 50 - 50
260 - 50 = 30x
210 = 30x
210/30 = 30x/30
210/30 = x
7 = x
So he has played 7 months when he spends $260