Question

这个式子是怎么化简出来的x/(x^2+1)-y/(y^2+1)=[(x-y)(1-xy)]/[(x^2+1)(y^2+1

Answer 1

=[y^2*x+x-y-x^2*y]/[(x^2+1)(y^2+1)]

=[(x-y)+xy(y-x)}/[(x^2+1)(y^2+1)]

=[(x-y)-xy(x-y)]/[(x^2+1)(y^2+1)]

=[(x-y)(1-xy)]/[(x^2+1)(y^2+1)]