\(\dfrac{x^2-9y^2}{x^2+xy-6y^2}=\dfrac{\left(x-3y\right)\left(x+3y\right)}{\left(x-2y\right)\left(x+3y\right)}=\dfrac{x-3y}{x-2y}\)

\(\dfrac{x^2+3xy+2y^2}{x^3+2x^2y-xy^2-2y^3}\)

\(=\dfrac{\left(x+y\right)\left(x+2y\right)}{x\left(x^2-y^2\right)+2y\left(x^2-y^2\right)}\)

\(=\dfrac{x+y}{x^2-y^2}\)

\(=\dfrac{1}{x-y}\)

\(\frac{x^2-y^2}{x^2-y^2+xy-yz}=\frac{1}{xy-yz}=\frac{1}{y\left(x-z\right)}\)

\(\dfrac{x^2-xy-6y^2}{x^2-9y^2}=\dfrac{\left(x-3y\right)\left(x+2y\right)}{\left(x-3y\right)\left(x+3y\right)}=\dfrac{x+2y}{x+3y}\)

\(\frac{xy^3-x^2}{x^2+xy}=\frac{x\left(y^3-x\right)}{x\left(x+y\right)}=\frac{y^3-x}{x+y}\)

\(=\dfrac{1-x}{xy\left(x-1\right)}=\dfrac{-1}{xy}\)

mình không biết nha

Nhớ k cho mình nha

Chúc các bạn học giỏi

a)\(\dfrac{x^2-4xy+4y^2}{xy-2y^2}\)

=\(\dfrac{x^2-4xy+\left(2y\right)^2}{y\left(x-2y\right)}\)

=\(\dfrac{\left(x-2y\right)^2}{y\left(x-2y\right)}\)

=\(\dfrac{x-2y}{y}\)

b)\(\dfrac{x^3-36x}{x^2+6x}\)

=\(\dfrac{x\left(x^2-6^2\right)}{x\left(x+6\right)}\)

=\(\dfrac{x\left(x+6\right)\left(x-6\right)}{x\left(x+6\right)}\)

= \(x-6\)

#Fiona 

Chúc bạn học tốt !