Question

An angle is 20 degrees less than thrice it's supplement. Find the measures of these angles

Answer 1

a + 20 = 3 (180-a)

a + 20 = 540 - 3 a

4 a = 520

a = 130
180-a = 50

Answer 2

X+20=3 (180-x)
X+20=540-3x
X+3x=540-20
4x=520
X=520/4
X=130