. In solving the equation (x + 2)(x – 2) = 32, Eric stated that the solution would be
x + 2 = 32 = x = 30
or
(x – 2) = 32 = x = 34
However, at least one of these solutions fails to work when substituted back into the original equation. Why is that? Please help Eric to understand better; solve the problem yourself, and explain your reasoning.

Question

. In solving the equation (x + 2)(x – 2) = 32, Eric stated that the solution would be
x + 2 = 32 => x = 30
or
(x – 2) = 32 => x = 34
However, at least one of these solutions fails to work when substituted back into the original equation. Why is that? Please help Eric to understand better; solve the problem yourself, and explain your reasoning.

anonymous · Answer

Multiply out (x+2)(x-2)=32
x^2-2x +2x -4 =32
Then simplify
x^2=36
x=6
You have to be careful of the signs