The sum of two complementary angles is 90°. for one pair of complementary angles, the measure of the first angle is 15 less than twice the measure of the second angle. write a system of equations that can be used to determine the measure of the first angle, a, and the measure of the second angle, b. •a+b=90 a-2b=15 •a+b=90 2b-15=a •a+b=90 2b+15=a •a+b=90 2a-15=b