Question

Two angles with measures (6x + 60) and (90) are supplementary. What is the value of x?

Answer 1

Supplementary angles add up to 180, so 
6x+60+90 = 180 and solve for x
6x= 30
x=5

Answer 2

supplementary means that the angles add to 180, so solve the equation 6x+60+90=180. 6x=30 x=5