1: establish the angles, basically label one x (the small one) and the other y (the bigger one)
2. supplementary angles add up to 180, so therefore you have the equation x + y = 180.
3. so y (the bigger one) is 8 less than 3 times the smaller one (x) therefore you come up with the equation y = 3x - 8
4. plug in the equation of the bigger one into the other equation
x + 3x - 8 = 180
(combine like terms)
4x - 8 = 180
5. solve the equation by adding 8 to 180, then by dividing by 4.
x should equal 47
6. plug in 47 into the x + y = 180 equation, subtract 47 from 180 and you end up with 133
i hope i explained it alright