Answer:
x^2 + 10x + 25 = 31
Explanation:
x^2 + 10x + (10/2)^2 = 6 + 25
x^2 + 10x + 25 = 6 + 25
x^2 + 10x + 25 = 31
The first step requires a bit of explanation. The way to complete the square is to take 1/2 the linear term (10x) and square it
1/2 10 = 5
5 squared = 25
That number must be added to the right side to maintain equality.