at one gym, there is a $12 start-up fee, and after that each month at the gym costs $20. at another gym, it costs $4 to startup, but after that, each month at the gym costs $22. after how many months will the cost of both gyms be the same?

4 months

Step-by-step explanation:

At the first gym, $12 is the start-up fee and after that each month at the gym costs $20.

At the second gym, $4 is the start-up fee and after that each month at the gym costs $22.

Let us assume that after x months the cost of both the gym will be the same.

Therefore,  

12 + 20x = 4 + 22x

⇒ 2x = 8

⇒ x = 4 months. (Answer)

n=9

step-by-step explanation:

7 times a number = 7n

decreased by 13 = 7n-13

same as is =

5 times the number = 5n

increased by 5 = 5n+5

7n-13 = 5n+5

2n=18

n=9