Question 312778
Let x = the angle
90 - x = the complement
180 - x= the supplement



x= 3(180 - x)-20

x = 540 - 3x-20


Add + 3x to each side:
4x = 520
x= 130 degrees = the angle
180 - x= 180 - 130 = 50 degrees = supplement.


Check:

The angle is 20 degees less than 3 times the supplement
130 = 150 - 20


It checks!!!  


By the way, it's always good to check these problems, because the first time I worked this I missed it!!  I found the error after I checked it.


Dr. Robert J. Rapalje, Retired