若x/y=2/7,求x^2-3xy+2y^2/2x^2-3xy+7y^2的值.
若(y-x)/xy=3,求分式(2x+3xy-2y)/(x-2xy-y)的值
若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知x/y=7/2,求2x+3xy+2y/x+2xy+y的值
已知x+y=4,xy=2,求代数式2(3x+2xy)+(2xy+3x+2y)-(4xy-7y)的值
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
x+y=8,xy=-2,求(5xy+4x+7y)+(6x-3xy)-(4xy-3y)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=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知x+y=3xy,求2x+2y-xy/x+y+2xy的值、
已知xy/x+y =3,求2x-3xy+2y/-x+3xy-y 的值.