a)\(\dfrac{3\left(x-y\right)^4+2\left(x-y\right)^3-5\left(x-y\right)^2}{\left(y-x\right)^2}=\dfrac{\left(x-y\right)^2\left[3\left(x-y\right)^2+2\left(x-y\right)-5\right]}{\left(x-y\right)^2}=3x^2-6xy+3y^2+2x-2y-5\)
b) \(\dfrac{\left(x-2y\right)^3}{x^2-4xy+4y^2}=\dfrac{\left(x-2y\right)^3}{\left(x-2y\right)^2}=x-2y\)
c) \(\dfrac{x^3+y^3}{x+y}=\dfrac{\left(x+y\right)\left(x^2-xy+y^2\right)}{x+y}=x^2-xy+y^2\)
a: \(\dfrac{3\left(x-y\right)^4+2\left(x-y\right)^3-5\left(x-y\right)^2}{\left(y-x\right)^2}\)
\(=\dfrac{3\left(x-y\right)^4+2\left(x-y\right)^3-5\left(x-y\right)^2}{\left(x-y\right)^2}\)
\(=3\left(x-y\right)^2+2\left(x-y\right)-5\)
b: \(\dfrac{\left(x-2y\right)^3}{x^2-4xy+4y^2}\)
\(=\dfrac{\left(x-2y\right)^3}{\left(x-2y\right)^2}\)
=x-2y
c: \(\dfrac{x^3+y^3}{x+y}\)
\(=\dfrac{\left(x+y\right)\left(x^2-xy+y^2\right)}{x+y}\)
\(=x^2-xy+y^2\)