a.\(\text{\(x^3z+x^2yz-x^2z^2-xyz^2\)}\)
\(=\left(x^3z+x^2yz\right)-\left(x^2z^2+xyz^2\right)=x^2z\left(x+y\right)-xz^2\left(x+y\right)\)
\(=xz\left(x-y\right)\left(x+y\right)\)
\(\text{ }\)
b.gọi biểu thức là P ta có :
\(P=p^{m+1}q\left(p-q^2\right)-pq^{n+1}\left(p-q^2\right)\)
\(P=\left(p-q^2\right)\left(p^{m+1}q-pq^{n+1}\right)=pq\left(p-q^2\right)\left(p^m-q^n\right)\)