Find the unknown lengths of the sides of each triangle.

-7

step-by-step explanation:

x^2 + 18x + 74 = (x + 9)^2 - 81 + 74

= (x + 9)^2 - 7.

so q = -7.

let m = monomial

let t = trinomial

so, m times t = t.

monomial times a trinomial = another trinomial.