Answer:
100°
Step-by-step explanation:
Let the angle = x
Its supplement = 180 -x
5*(180 - x ) - x = 300
5*180 - 5*x - x= 300 {Distributive property}
900 - 5x - x = 300 {Combine like terms}
900 - 6x = 300 {Subtract 900 from both sides}
-6x = 300 - 900
-6x = -600 {Divide both sides by (-6)}
x = -600/-6
x = 100
