已知1/x-1/y=2,求(3x+5xy-3y)/(x-xy-y)的值
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知1/X-1/Y=-2,求3X-5XY-3Y/-X+3XY+Y的值
已知1/x-1/y=3,求x-2xy-y/5x+3xy-5y的值
已知1/x+1/y=5,求x+2xy+y/2x-3xy+2y的值
已知:1/X+1/Y=5,求 2x-3xy+2y/x+2xy+y的值,
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
已知xy/x+y=2,求代数式3x-5xy+3y/-x+2xy-y的值
已知x-y=2xy,求代数式3x-5xy-3y/x+xy-y的值
已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值
已知1/x+1/y=5,求(3x-5xy+3y)/(x+xy+y)的值?
已知x/1-y/1等于3,求x-2xy-y/5x+3xy-5y的值