|3x-y+5|+(2x-y+3)²=0 求x=?y=?
|x+2y+3|+(2x+y)²=0求x²-xy+y²
已知3x²+xy-2y²=0(x≠0,y≠0),求x/y-y/x-x²+y²/x
|3x-y+5|+(2x-y+3)²=0 求x=?y=?
已知(x+2)²+|x+y+5|=0,求3x²y+{-2x²y-[-2xy+(x²
已知x²+y²-4x+6y+13=0,求x²+2y/x²-3y²的值
x²-2x+y²+6y+10=0,求—9(x+y)²+(3x-2y)(2y+3x)的值
已知X²-5XY+6Y²=0,求(X²+3XY)\2Y²的值
已知xy=-2,x-y=3,求(x+y)(x-y)-y²+(x-y)²-(6x²y-2xy
已知x/y=3,求x²+2xy-3y²/x²-2xy+y²
已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值
x/y=2,求分式x²-xy+3y²/x²+xy+6y²
求代数式3x²y+5x-0.5x²y+3.5x²y-2的值,其中x=1/5,y=7