(1)3xy³/x²y=( )/x (2)4/x-1=( )/(x-1)(x+1)

问题描述:

(1)3xy³/x²y=( )/x (2)4/x-1=( )/(x-1)(x+1)

(1)3xy³/x²y=(3y² )/x (2)4/x-1=( 4x+4)/(x-1)(x+1)为什么是4x+44*(x+1)/(x+1)*(x-1)=4/(x-1)