Answer:
x = 10
Step-by-step explanation:
Supplementary angles add up to equal 180°
Thus, 10x + 80 = 180
Now that we have identified the equation we solve for x
10x + 80 = 180
step 1 subtract 80 from each side
80 - 80 cancels out
180 - 80 = 100
we now have 100 = 10x
step 2 divide each side by 10
100 / 10 = 10
10x / 10 = x
we're left with x = 10
