Answer:
x = 21
Step-by-step explanation:
Step 1: Make an expression
Since they are supplements, that means that they add up to 180 degrees.
3x + 6 + 5x + 6 = 180
Step 2: Combine like terms
3x + 6 + 5x + 6 = 180
(3x + 5x) + (6 + 6) = 180
8x + 12 = 180
Step 3: Subtract 12 from both sides
8x + 12 - 12 = 180 - 12
8x = 168
Step 4: Divide both sides by 8
8x / 8 = 168 / 8
x = 21
Answer: x = 21
