Question

solve this question

Answer 1

Given two angles are complementary
let one Angle be x and other will be 90-x
$x = \frac{7}{2} (90 - x) \\ 2x = 630 - 7x \\ 9x = 630 \\ x = 70$
hence the angle are 70 and 20

Answer 2

let one of them angle is x
then according to question another angle is 7/2 x.
we know that
the sum of complementary angles are 90 degree.
$\frac{7}{2} x + x = 90 \\ \frac{9}{2} x = 90 \\ x = 20$
another one is 70
hence
answer 3 is correct