Given:
The values of input and outputs are given
Output is increasing by 9 for the increase in x values.

525/15 = 35 they would need to sell 35 tickets for there concert to cover the cost of the gym. <span />
Answer:
you have to do it yourself
Step-by-step explanation:
x = -12
y = x/2 + 9
y = -12/2 + 9
y = -6 + 9
y = 3