SOLUTION: How large is an angle whose supplement contains 12 degrees less than three times its complement?

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Question 172337: How large is an angle whose supplement contains 12 degrees less than three times its complement?
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
lets call a the angle in question and the supplement s and the complement c
:
a+s=180....lets rewrite this in terms of s--->s=180-a remember s is the supp
a+c=90.....lets rewrite this in terms of c--->c=90-a..remember c is the comp
:
s=3c-12......now plug the value for s and c into this equation.
:
180-a=3(90-a)-12
:
180-a=270-3a-12
:
2a=78
:
highlight%28a=39%29degrees