Question

a/ \(\dfrac{x^2}{x^2-y^2}\) - \(\dfrac{2\text{x}y}{x^2-y^2}\) + \(\dfrac{y^2}{x^2-y^2}\)

b/ \(\dfrac{x+y}{x-y}\) - \(\dfrac{x-y}{x+y}\) - \(\dfrac{4y^2}{x^2-y^2}\)

giúp mình với huhu mình cần gấp

 

Answer 1

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

Answer 2

a.\(\dfrac{\left(x-y\right)^2}{x^2-y^2}\)
b.

Answer 3

=3424,998

Answer 4

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

Answer 5

a,=x2−2xy+y2(x−y)(x+y)=(x−y)2(x−y)(x+y)=x−yx+yb,=x2+2xy+y2−x2+2xy−y2−4y2(x−y)(x+y)=4xy−4y2(x−y)(x+y)=4y(x−y)(x−y)(x+y)=4yx+y