Question

已知x/y=1/2,求2x/(x²-2xy+y² )* (x²-y²/x+y)+

Answer 1

x/y=1/2

y=2x

2x/(x²-2xy+y² )* (x²-y²/x+y)+2y/x-y

=2x/(x-y)²*(x+y)(x-y)/(x+y)+2y/(x-y)

=2x/(x-y)+2y/(x-y)

=2(x+y)/(x-y)

=2(x+2x)/(x-2x)

=6x/-x

=-6