Answer:
x = 19
Explanation:
You are given two supplementary angles with measures (x+19) and (7x+9) and you want the value of x.
Supplementary angles
The angles shown are a "linear pair," which are supplementary by definition. That is, their sum is 180°.
(x +19) +(7x +9) = 180
8x +28 = 180 . . . . simplify
8x = 152 . . . . . . . . subtract 28
x = 19 . . . . . . . . . . divide by 8