If WXYZ is an isosceles trapezoid with base angles X and Y. (Problem 23 shows that ∠X ≅ ∠Y...

If WXYZ is an isosceles trapezoid with base angles X and Y. (Problem 23 shows that ∠X ≅ ∠Y.) If m∠X = −2q + 71 and m∠Y = −5q + 32 for some quantity q, find m∠X.

[UCSMP, p. 239]