已知x+y=5,xy=6求(x+1)(y-1)
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+2(xy+y)的值
已知X+Y=-1,xy=-2,求代数式-5(x+y)+(x-y)+(xy+y)的值
已知x+y=3,xy=1,求代数式5xy+4x+7y+6x-3xy-4xy+3y的值.
已知1/x-1/y=3,求x-2xy-y/5x+3xy-5y的值
已知1/x-1/y=3,求代数式5x+xy-5y除以x-xy-y的值.
已知1/x+1/y=5,求(3x-5xy+3y)/(x+xy+y)的值?
已知1/x+1/y=5 求2x-3xy+2y/3x+2xy+3y
已知1/x+1/y=5,求x+2xy+y/2x-3xy+2y的值
已知1/x-1/y=5 求分式-x+xy+y/2x+7xy-2y
已知1/x+1/y=3,求(3x-5xy+3y)/(x-2xy+y)
已知1/x-1/y=5,求分式y+xy-x/2x+7xy-2y的值.