Question

y / 2x²-xy+4x / 2xy-x²
1 / (x-y)(y-z) + 1 / (y-z)(z-x) + 1 / (z-x)(x-y)
x-y / xy + y-z / yz + z-x / zx
Thực hiện pt

Answer 1

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

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

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

\(=\dfrac{2y^2-xy+8x^2-4xy}{x\left(2x-y\right)\left(2y-x\right)}=\dfrac{8x^2-5xy+2y^2}{x\left(2x-y\right)\left(2y-x\right)}\)

b: \(\dfrac{1}{\left(x-y\right)\left(y-z\right)}+\dfrac{1}{\left(y-z\right)\left(z-x\right)}+\dfrac{1}{\left(z-x\right)\left(x-y\right)}\)

\(=\dfrac{z-x+x-y+y-z}{\left(x-y\right)\left(y-z\right)\left(z-x\right)}=0\)