x^2+y^2=7,xy=-2,求5x^2-3xy-4y^2-11xy-7x^2+2y^2的值
x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)的值
已知x+y=4,xy=2,求代数式2(3x+2xy)+(2xy+3x+2y)-(4xy-7y)的值
x^2+y^2=7,xy=-2,求5x^2-3xy-4y^2-11xy-7x^2+2y^2的值
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y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4X-5XY+4Y 除以X+XY+Y 的值
已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值
已知x-y=2xy,求代数式3x-5xy-3y/x+xy-y的值
xy=-2,x+y=3,求代数式(4xy+12y)+[7x-(3xy+4y-x)]
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值