Answer:
see below
Step-by-step explanation:
They are completing the square
x^2 +12x +29
Take the coefficient of the x term
12
Divide by 2
12/2 = 6
Square it
6^2 = 36
Add 36 and subtract 36
(x^2 +12x +36) -36 +29
Inside the parentheses becomes ( x+6)^2
