已知A=2x^2-3xy+y^2+2x+2y,B=4x^2-6xy+2y^2-3x-y
已知:A=X*X-3xy+y*y,B=2x*x+xy-3y*3y.求A+B,A-B,A+2B
已知xy=-2,x-y=3,求(x+y)(x-y)-y^2+(x-y)^2-(6x^2y-2xy^2)÷2y
已知x-y=4xy,则2x+3xy-2yx-2xy-y
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y,若x=
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²-3x-y,若x
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y.若x
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=-2,求x^2-2xy-3y^2/x^-6xy
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xy=-2,x-y=3,求(x+y)(x-y)-y²+(x-y)²-(6x²y-2xy