please solve this ASAP. I need this done but I can't figure it out

Answer:
x = 61
Step-by-step explanation:
Supplementary angles add up to 180 degrees. We can create an equation and solve for x.
(2x + 6) + (x - 9)= 180
~Combine like terms
3x - 3 = 180
~Add 3 to both sides
3x = 183
~Divide 3 to both sides
x = 61
Best of Luck!