What are the solutions of the equation (x + 2)^2+ 12(x + 2)-14=0? Use u substitution and the quadratic formula to solve

Step-by-step explanation:

Obviously, we are letting u = x + 2. So what we have when we rewrite using this substitution is

and we plug that into the quadratic formula with

a = 1, b = 12, c = -14:

which can be simplified to

and a bit more to

and a tiny bit more to

and finally to

and plug back in for u:

x + 2 = -6 ± 5√2 and then subtract the 2 to get

x = -8 ± 5√2

expression #3 is not equivalent. the others are.