已知x+y=a,xy=b,求x+y^2,x^2-xy+y^2
已知:A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
x²(x+y)(y-x)-xy(x+y)(x-y) 已知a+b=4,ab=-2,求多项式3a²b+3
已知x+y=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)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=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3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
已知x-y/xy=3,求分式2x+3xy-2y/x-2xy-y的值.
已知xy/x+y=3,求代数式2x-5xy+2y/x-3xy+y