The square root of (x + 2)² is (x + 2) .
The square roots of 4 are +2 and -2 .
So the resulting equation was x + 2 = ± 2 .
From there, it was pretty easy for Theo to find the solutions
to the original equation . . .
If (x + 2) = +2 , then x = 0 .
If (x + 2) = -2 , then x = -4 .