已知x+2y=4,xy=-2,求3x+2xy+6y的值,
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知xy/x+y=6,求3x-2xy+3y/-x+3xy-y的值.
已知x+y=4,xy=-2,求代数式3(xy+2y)-(xy-6x)的值
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x/y=2,求 [x^2-xy+3xy^2 ] / [ x^2+xy+6y^2]的值
已知x+y=4,xy=2,求x+y+3xy的值
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
已知x-y=4,xy=-2,求代数式(2x+3y-2xy)-(x+4+xy)-(3xy+2y-2x)的值
已知x-y/xy=3,求分式2x+3xy-2y/x-2xy-y的值.
已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.
已知x+y=3xy,求2x+2y-xy/x+y+2xy的值、