Interior angles on parallel lines cut by a traversal are supplementary (they add up to 180°). These can be identified as "c" angles, due to their shape. Knowing this, we can figure out the value of x:
7x+(2x+36)=180
7x+2x+36=180
Simplify the equation
9x+36=180
Collect like terms
9x=144
Divide by 9 on both sides to isolate x
x=16
