(8x^2)-128
Well you cannot simplify except by taking away the brackets.
Those brackets are meaningless and mildly annoying so get rid of them.
If you are meant to factorise then take out the 8
8(x^2-16)
Now you have a difference of 2 squares.
8(x-4)(x+4)
(8x^2)-128=0
(8x^2)=128 divide both sides by 8
x^2=16 take the sqrt of both sides
x=4
