Find the measures of an angle and its complement

The sum of three times an angle and twice its complement is 215. What are the measures of the angles?

x = the angle
90 - x = its complement   {complementary angles add up to 90°} 

3x + 2(90 - x) = 215   {sum of three times the angle and its complement is 215}
3x + 180 - 2x = 215   {used distributive property}
x + 180 = 215   {combined like terms}
x = 35   {subtracted 180 from each side}
90 - x = 55   {substituted 35, in for x, into 90 - x} 

the angle is 35°
its complement is 55°

- Algebra House