Đáp án:
$\begin{array}{l}
e){\left( {{x^2} + 1} \right)^2} - 4{x^2}\\
= {\left( {{x^2} + 1} \right)^2} - {\left( {2x} \right)^2}\\
= \left( {{x^2} + 1 + 2x} \right)\left( {{x^2} + 1 - 2x} \right)\\
= {\left( {x + 1} \right)^2}{\left( {x - 1} \right)^2}\\
f)\left( {{y^3} + 8} \right) + {y^2} - 4\\
= {y^3} + {y^2} + 4\\
= ??\\
g)1 - \left( {{x^2} - 2xy + {y^2}} \right)\\
= {1^2} - {\left( {x - y} \right)^2}\\
= \left( {1 - x + y} \right)\left( {1 + x - y} \right)
\end{array}$
