一道数学题!关于分式的!
已知X/1-3/Y=3
求3X-5XY-3Y除以(/)X-2XY-Y
好得话加分!!5呵呵~~
参考答案:1/x - 1/y =3
(y-x)/xy =3
y-x =3xy
x-y=-3xy
(3x-5xy-3y)/ (x-2xy-y)
=(3(x-y)-5xy )/((x-y)-2xy)
=(3*(-3xy)-5xy)/((-3xy)-2xy)
=-14/(-5)
=14/5
已知X/1-3/Y=3
求3X-5XY-3Y除以(/)X-2XY-Y
好得话加分!!5呵呵~~
参考答案:1/x - 1/y =3
(y-x)/xy =3
y-x =3xy
x-y=-3xy
(3x-5xy-3y)/ (x-2xy-y)
=(3(x-y)-5xy )/((x-y)-2xy)
=(3*(-3xy)-5xy)/((-3xy)-2xy)
=-14/(-5)
=14/5