If the original angle is x degrees then its supplement is 180 - x degrees.
we have the equation:-
180 - x = 3x + 20
160 = 4x
x = 40
The original angle is 40 degrees and its supplement is 140 degrees
1 - 9
2 - 87
3 - -2
4 - -9
that’s the answers for them :), have a great day !! :)