Question

The difference of two supplementary angles is 40`. Find the angles.

Answer 1

Let one angle be X then
X + X +40 = 180
2X = 180 - 40 = 140
X = 70 degree
Other angle is 110 degree

Answer 2

Angle= x
Supplementary angle= 180-x

$x - (180 - x) = 40 \\ x - 180 + x = 40 \\ 2x = 220 \\ x = 110. \\ 180 - x = 70.$
Angles are 110° and 40°.

!