please answer with exlanation

Question

Points X, Y, and Z are collinear. What is m∠XYQ?

m∠XYQ =

Answer 1

Since points x, y, and z are collinear, they form a straight angle. Hence angles XYQ and ZYQ are supplementary, meaning that their measures sum to 180°:

m∠XYQ + m∠ZYQ = 180º

10a + 2 + 5a - 2 = 180º

Solve for a. Once you have the value of a, m∠XYQ = 10a + 2. The units are degrees (º).