Here's the question you clicked on:
jalinnn
(x + 2)(x - 2)
Will you take care of this freckles?
Recall in your earlier post that: \[(x-y)(x+y)=x(x+y)-y(x+y)=x(x)+x(y)-y(x)-y(y)\] \[=x^2+xy-xy-y^2=x^2-y^2 \]
\[(x-y)(x+y)=x^2-y^2 \]
So you are multiplying conjugates all you have to do is do the first^2-last^2