Name a pair of complementary angles

Having a hard time understanding this question (see attachment).

Hich equation can pair with x + 2y = 5 to create an inconsistent system? 2x + 4y = 3 5x + 2y = 3 6x + 12y = 30 3x + 4y = 8

An isosceles trapezoid with a perimeter of 42 inches. each of the congruent non parallel sides is 5 inches long, and the trapezoid is 3 inches tall. how long are the two parallel sides? a. 10 in, 22 in b. 16 in, 16 in c. 10 in, 16 in d. 12 in, 20 in