已知x分之3-y分之2=3,则7xy+9y-6x分之2x-3y-xy=3/x -2/y=3等式两边同乘以xy3y-2x=3xy(2x-3y-xy)/(7xy+9y-6x)=[-(3y-2x)-xy]/[3(3y-2x)+7xy]=(-3xy-xy)/[3·(3xy)+7xy]=(-4xy)/(16xy)=-1/4很高兴为您解答,希望对你有...