Question

I'm having trouble with this question any help?

Answer 1

Answer is 2) 49/4

x^2 +7x = 11

left side
x^2 + 2 (x) (7/2) + 49/4 
= (x + 7/2)^2

Answer 2

The added number is 49/4. Proof:

x² + 7x = 11
x² + 7x + 49/4 = 11 + 49/4
(x+7/2)² = 11+49/4