Question

Angles (30-a) and (125+2a) are supplement. Find these angles.

Answer 1

Given angles are (30-a) and (125+2a) , 
also given that the angles are supplementary,
⇒30-a+125+2a = 180°
⇒155+a = 180°
⇒a = 180-155 = 25 .
First angle (30-a) = (30-25) = 5°
Second angle [125+(2×25)] = 125 + 50 = 175°
Therefore , the angles are 5° , 175° .

Answer 2

30-a +125+2a=180
155+a=180
a=180-155
a=25
so,
30-a
30-25=5
125+2a
125+2*25
125+50
175
hence, 175 and 5 are angles