Question

What number would you add to both sides of x^2+7x= 4 to cornplete the square?

•2 ^2
•7^2
• 7^2/2
• [7/2]^2

Answer 1

49/4

Explanation:

⇒ x2 + 7x +49/4 = 4 + 49/4

⇒ {4x2 + 28x + 49}/4 = {16 + 49} /4

⇒ {4x2 + 28x + 49} = 16 + 49

⇒ (2x + 7)2 = 65 [since a2+ 2ab + b2 = (a + b)2]

⇒ (2x + 7)2 = (√65)2