如果X-2Y=7,XY=3,则2XY-4Y+2Y+5=( )

已知x-y=4xy，则2x+3xy-2yx-2xy-y [-(x-y)^2/xy]^-4*(y^2-xy/x)^3*(x^4/y^10)÷(xy-y^2/x)^-5=-y(y- xy=-2,x+y=3,求代数式（4xy+12y)+[7x-(3xy+4y-x)] 已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y= x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值 如果x+y=4,xy=-1,那么多项式2x+3y-3xy+4xy-3x-4y+7的值为 如果1\x-1\y=2,那么3x+5xy-3y\x-xy-y等于多少 如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值. （-3x^y+2xy)-( )=4x^+xy 已知xy/x+y=2,则代数式3x-5y+8y/-x+3xy-y的值 若x+y=-1,则x^4+5x^3y+x^2y+8x^2y^2+xy^2+5xy^3+y^4=( ) 已知xy^2=-2,求-xy（x^2y^5-xy^3-y)的值.