已知x+y,且x²-2x=7,y²-2y=7求①x+y②2x+xy+y²
已知x+y,且x²-2x=7,y²-2y=7求①x+y②2x+xy+y²
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x-7y=0,且y≠0,求2x²﹢xy-3y²分之x²-3xy+y²的值
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
已知 x²-xy+2y²=14,且x-y=6,求x-2y
已知2x-y=10,求式子[(x^2+y^2)-(x-y)^2+2y(x-y)]/4y (4xy-2y²)/4
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
已知xy²=-6,求xy(x^3y^7-3x^2y^5-11.5y)的值
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知x≠y,且x²-x=2,y²-y=2,求x²-xy+y²的值
已知x-3y=0,求(x²-2xy+y²/x-y)-2y的值
已知(x+y-7)²+|2x-3y-4|=0 求xy得值