Question 1009650
You would be interested in grouping, or movement of terms to try to factorize, if for Algebra 2.


You just need to try different placements of the terms.
{{{x^2(x^2-1)+4-4x^2}}}
{{{x^2(x^2-1)+4(1-x^2)}}}
Notice the two factors which appear very much alike but are not equal!
Trick is multiply the second expression by {{{-1}}}, TWICE.
{{{x^2(x^2-1)+(-1)4(-1)(1-x^2)}}}
{{{x^2(x^2-1)-4(x^2-1)}}}
Factor the whole expression.
{{{(x^2-1)(x^2-4)}}}
Observe, two quadratic factors according to difference of squares.
{{{highlight((x-1)(x+1)(x-2)(x+2))}}}