What are the coordinates of a, b,c ?

let m = monomial

let t = trinomial

so, m times t = t.

monomial times a trinomial = another trinomial.

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)