For which equation does it make the most sense to solve by completing the square? a) 5x² + 3x = 9b) x² + 20x = 52c) x^2−8=1d) 3x^2−x+17=0

Completing the square is a method used to solve a quadratic equation by changing the shape of the equation so that the left side is a perfect square trinomial.
 The following equation makes more sense to solve it complete squares:
 x² + 20x = 52
 We have then:
 x² + 20x + (10) ^ 2 = 52 + 100
 (x + 10) ² = 152
 
 The most sense to solve by completing the square is for:
 B) x² + 20x = 52