The expression representing the complement of an angle (x):
(90 - x)
:
The expression representing the supplement of an angle (x)
(180 - x)
:
"the complement of an angle is 18 degrees more than 1/3 its supplement."
(90 - x) = (180-x) + 18
:
90 - x = 60 - x + 18; found one third of 180
:
90 - x = 78 - x
:
90 - 78 = -x + x
:
12 = +x
Multiply equation by 3 to get rid of the denominator
3(12) = 3*x
36 = 2x
x =
x = 18 degrees