Two angles are supplementary. if one measures x and the other angle measures x+ 30, what is the value of x ?

x = 75

Remember: supplementary angles add up to 180°.

Form your equation.
x + x + 30 = 180

Solve for x.
x + x + 30 = 180              Combine like terms
2x + 30 = 180                  Subtract 30 from both sides
2x = 150                          Divide by 2 to both sides
x = 75                              Answer!