How do I find xy^-2(xy^2 - 4y^4) ??
To simplify xy^-2(xy^2 - 4y^4), you would write it as fraction (not forgetting the parentheses at the right places):
xy^-2(xy^2 - 4y^4)
= (x/y²)(xy^2 - 4y^4)
= (x/y²) * y²(x-4y²)
= x * (x-4y²)
= x²-4xy²
xy^-2(xy^2 - 4y^4)
= (x/y²)(xy^2 - 4y^4)
= (x/y²) * y²(x-4y²)
= x * (x-4y²)
= x²-4xy²