1.已知x+y=6,xy=7,求(3x+y)+(x+3y) 2.(1-1/2)(1-1/3
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+7xy-3y/2x-3xy-2y
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
已知x-y=3,xy=1,求(-2x+2x+3y)-(3xy+2y-2x)-(x+4y+xy)
1.已知:X+Y+Z=3Y=2Z,求X/X+Y+Z的值 2.已知:1/X-1/Y=3,求2X+3XY-2Y/X-2XY-
已知:xy+x=-1,xy-y=-2,求多项式-x-[2y-2(xy+x)的平方+3x]+2[x+(xy-y)的平方]的
已知1/x+1/y=5 求2x-3xy+2y/3x+2xy+3y
已知1/x+1/y=3,求分式3x-2xy+3y/x+xy+y的值
已知1/x+1/y=3,求(3x-5xy+3y)/(x-2xy+y)
已知1/X-1/Y=-2,求3X-5XY-3Y/-X+3XY+Y的值
已知1/x-1/y=3,求(3x+4xy-3y)/(x-2xy-y)的值