Two Angles are Supplementary when they add up to 180°.
Therefore we have the equation:
m∠1 + m∠2 = 180°
(x - 39) + (x + 61) = 180
x - 39 + x + 61 = 180
2x +22 = 180 subtract 22 from both sides
2x = 158 divide both sides by 2
x = 79
m∠1 = (x - 39)° → m∠1 = (79 - 39)° = 40°
m∠2 = (x + 61)° → m∠2 = (79 + 61)° = 140°
Answer: m∠1 = 40° and m∠2 = 140°
