Since we know these angles are supplementary (add to 180) because they are on a straight line, we can add them together, set that to 180 and solve for x
5x+20+3x-8=180 (combine like terms)
8x+12=180 (subtract 12 from both sides)
8x=168 (divide both sides by 8)
X=21
Then we can find both angles
Angle 1:
5(21)+20
105+20
=125
Angle 2:
3(21)-8
63-8
=55
Hope this helps
