已知3x-4y=0,求x^2-3xy/3x^2+y^2的值
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知y-x-2xy=0,求3x+xy-3y/y-xy-x的值
已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)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^2+3xy-4y^2=0(y≠0),求x-y/x+y的值.
已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)*(x-y)的值
已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)*(x-y)的值.
已知x-3y=0,求(2x+y)(x-y)/x^2-2xy+y^2的值
已知x-3y=0,求2x+y/x-2xy+y乘(x-y)的值
已知x+y=4,xy=2,求x+y+3xy的值