3x+x-2+y=18

3x+x-2+y=18 3^x+2x=y,x (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (x+y)(2x-3y)=? x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 {x-3y=2,2x+y=18 x=y+3 2x+y=18 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 (计算方程组x+y)/2=6-(x-y)/3,6(x+y)-5(x-y)=18 2x-1-3(y-2)=x 2(x-1)-y=4y-18, 2x-1-3(y-2)=x 2(x-1)-y=4y-18, 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 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 (x^3-2x^2+xy^2)/(x-y)+(x+y)(y-x)=? 若2x=3y,则(x*x+y*y)/x*x=?