algebraic expression

Question

One of two supplementary angles is 45 degrees less than four times the other angle. Find the measure of each angle

Answer 1

Set one angle is x, then the supplementary angle will be 180-x

so you can write the equation: 

x= 4(180-x)-45

x=720-4x-45

5x=675

x=135

so the two angles are 135, 45.

Answer 2

a + 4a - 45 = 180

5a = 225

a = 45

 

4(45) - 45 = 3(45) = 135