已知2x-y=3,则10-6x+3y=

已知x-2y=3,则(2x+y-6)/(3x-y-9)=? 已知(3x+y+6)²+|x+y+2|=2,则x=,y=. 已知-x+y=3,则2(x-y)2次方-4(x-y)+6 已知x,y满足约束条件 2x+5y>=10 2x-3y>=-6 2x+y 已知x,y满足约束条件{2x+5y>=10,2x-3y>=-6,2x+y 已知x-y-3绝对值+(2x+2y+10)的平方=0,则(x+y)(x-Y)= 已知实数x,y满足2x+5y>=10;2x-3y>-6;2x+y 已知2x=3y,则y分之x=< >,y分之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：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) 已知|x+y-3|+(x-y)2=0则 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 比例线段：已知x/y=2/3,则 x/x+y= ,x-y/x+y= 要过程! 已知x,y为实数,根号3x+4 +y^2-6Y+9=0则x+y=? 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy) 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y