In the diagram, what is the value of x?
A. 144°
B. 28°
C. 5°
D. 36°

Remark
You can show that x and 4x are supplementary. The angle added to x on the same side of traversal is equal to 4x.
x + 4x therefore = 180 degrees. Add the like terms on the left.
5x = 180 degrees. Divide by 5
5x/5 = 180/5
x = 36
Answer x is 36 degrees. D.