a.\(\left(x-\dfrac{x^2+x^2}{x+y}\right).\left(\dfrac{1}{y}+\dfrac{2}{x-y}\right)\)
\(=\left(\dfrac{x^2+xy-2x^2}{x+y}\right)\left(\dfrac{x-y+2y}{y\left(x-y\right)}\right)\)
\(=\left(\dfrac{xy-x^2}{x+y}\right)\left(\dfrac{x+y}{y\left(x-y\right)}\right)\)
\(=-\left(\dfrac{x\left(x-y\right)}{x+y}\right)\left(\dfrac{x+y}{y\left(x-y\right)}\right)\)
\(=-\dfrac{x}{y}\)
b.\(\dfrac{2}{xy}:\left(\dfrac{1}{x}-\dfrac{1}{y}\right)-\dfrac{x+y}{\left(x-y\right)^2}\)
\(=\dfrac{2}{xy}:\left(\dfrac{y-x}{xy}\right)-\dfrac{x+y}{\left(x-y\right)^2}\)
\(=\dfrac{2}{xy}.\dfrac{xy}{y-x}-\dfrac{x+y}{\left(x-y\right)^2}\)
\(=-\dfrac{2}{x-y}-\dfrac{x+y}{\left(x-y\right)^2}\)
\(=\dfrac{2x+2y-x-y}{\left(x-y\right)^2}\)
\(=\dfrac{x+y}{\left(x-y\right)^2}\)
a) = \(\left(\dfrac{x\left(x+y\right)-2x^2}{\left(x+y\right)}\right).\left(\dfrac{x-y+2y}{y\left(x-y\right)}\right)\)
\(=\dfrac{-x^2+xy}{x+y}.\dfrac{x+y}{xy-y^2}=\dfrac{xy-x^2}{xy-y^2}=\dfrac{x\left(y-x\right)}{-y\left(y-x\right)}=-\dfrac{x}{y}\)
Mn giải giúp mik vs ạ 🥺 mình đang cần gấp. Cảm ơn mn nhiều