Supplementary angles add to 180 while complementary angles add to 90 degrees.
(180-x)= 4(90-x)
Distribute on the right
180-x=360-4x
Add 4x to both sides
180+3x=360
Subtract 180 from both sides
3x=180
Divide both sides by 3
x=60
Final answer: 60 degrees
