已知x+2y=6,则3x+6y—3=?
已知x-2y=3,则(2x+y-6)/(3x-y-9)=?
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为实数,根号3x+4 +y^2-6Y+9=0则x+y=?
已知x-5y=0(y≠0),则代数式2x-3y/3x+6y
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
已知6x+2y/9x-3y=6,那么(3x+y)平方/x平方-y平方
已知x,y满足约束条件{2x+5y>=10,2x-3y>=-6,2x+y
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知x+2y=6,则3x+6y—3=?
已知xy=-2,x-y=3,求(x+y)(x-y)-y²+(x-y)²-(6x²y-2xy