已知xy分之x+y=3,求-x+2xy-y分之2x-3xy+2y/的值

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已知xy分之x+y=3,求-x+2xy-y分之2x-3xy+2y/的值已知xy分之x+y=3,求-x+2xy-y分之2x-3xy+2y/的值已知xy分之x+y=3,求-x+2xy-y分之2x-3xy+

已知xy分之x+y=3,求-x+2xy-y分之2x-3xy+2y/的值
已知xy分之x+y=3,求-x+2xy-y分之2x-3xy+2y/的值

已知xy分之x+y=3,求-x+2xy-y分之2x-3xy+2y/的值
xy分之x+y=3
所以
1/x+1/y=3
(2x-3xy+2y)/(-x+2xy-y) 分子分母同除以xy
=[2(1/x+1/y)-3]/[-(1/x+1/y)+2]
=(6-3)/(-3+2)
=-3

3

x-y分之xy= - 3分之1 xy分之(x-y)=-3 x-y=-3xy x-2xy-y分之2x+3xy-2y =(-6xy+3xy)/(-3xy-2xy) =3/5

(x+y)/(xy)=3 1/x +1/y=3 x=y/(3y-1)
(2x-3xy+2y)/(-x+2xy-y)= -3