What value of x would make RST and STU supplementary?

Answer:
33 degrees
Step-by-step explanation:
Supplementary angles add up to 180 degrees. So take (4x)+(x+15)=180. Simplify this to 5x+15=180, move 15 to the right by subtracting. 5x=180-15, 5x= 165. Now divide by 5, x=165/5, which is x= 33 degrees.