Question

Вычислить
$(x^{-1} - 2y^{-3})^2$

Answer 1

$(x^{-1}-2y^{-3})^{2} = ( frac{1}{x} -2* frac{1}{y^{3}} )^{2} = ( frac{1}{x} -frac{2}{y^{3}} )^{2} = frac{(y^{3}-2x)^{2}}{x^{2}y^{6}} = frac{y^{6}-4xy^{3}+4x^{2}}{x^{2}y^{6}}$