1/x-1/y=5求(-x+xy+y)/(2x+7xy-2y)
1/x-1/y=5求(-x+xy+y)/(2x+7xy-2y)
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
已知1/x-1/y=5 求分式-x+xy+y/2x+7xy-2y
已知1/x-1/y=5,求分式y+xy-x/2x+7xy-2y的值.
已知1/X-1/y=5,求分式(y+xy-x)/(2x+7xy-2y)的值
1/x-1/y=2 求(2x+3xy-2y)/(x-xy-y)的值
1/x-1/y=4,求分式(3x+xy-3y)/(x-2xy-y)
已知x+y=1,xy=-2,试求代数式(xy+5x-2y)-(-3xy+2x-5y)的值.
已知x+y=1,xy=-2,试求代数式(xy+5x-2y)-(-3xy+2x-5y)的值
已知(x+2)*+|y+1|=0求5xy*-{2x*y-【3xy*-(4xy*-2x*y)】}的值
1.已知x+y=-4,xy=3,求5(2分之1xy+2y)+[6x-(2xy+y-3x)]的值
x(x-1)-(x平方-y)=-3,求x平方+y平方-2xy