Question in the picture

Answer:
19
Step-by-step explanation:
Given m is parallel to N:
The sum of given agles is equal to 180 since they are supplementary
8x - 7 + x + 16 = 180 add like terms
9x + 9 = 180 subtract 9 from both sides
9x = 171 divide both sides by 9
x = 19