Complementary angles add up to 90 degrees. The first angle is "x" and the second is "x-54". So you add them up and get it equal to 90. Like 2x-54=90, them you solve and you will get x=72. That is the first angle which is 72 degrees. Then to get the second angle you take 90 and subtract 72 and get 18 degrees which is the second angle.
