John's monthly paycheck consists of $4,000 plus a 9% commission on all of his sales. during one month, john earned $11,650. what were his sales during that month?

The problem statement tells us ...

... paycheck = 4000 + 0.09×sales

and that the paycheck amount is 11650. Substituting that into the above equation and solving for sales, we have ...

... 11650 = 4000 + 0.09×sales

... 7650 = 0.09×sales . . . . . . . . . . subract 4000

... 7650/0.09 = sales = 85000 . . . divide by 0.09

John's sales during that month were $85,000.

x is the total time in minutes for the free response

you are given number of questions as 15 - m and time per item as 8 minutes

to find x multiply the two givens together:

x = 8 * (15-m) = 8(15-m)