x/2+y/3=2 2x+3y=28怎么解

2x=y 3y=x怎么解 x-3y=2 y=x 怎么写 x^2-4xy+3y^2=（x-3y)(x-y)x^2-4xy+3y^2 怎么分解成（x-3y)(x-y) (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)=? 二元一次方程(x+y)/2+(x-y)/3=6,4(x+y)-5(x-y)=2怎么算 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 （x+2y)×（x+2y)-2(x-y)×（x+y)+2y(x-3y) 其中x=2 y=二分之一 要简便运算谁能告诉我《（x+2y)×（x+2y)-2(x-y)×（x+y)+2y(x-3y) 其中x=2 y=二分之一 》怎么写吗 【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 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 (x+y)(x-y)+3y^2怎么做? 3x*5y+2x*6y=2.7*(3x+2x)怎么解 {2X=5(X+Y)3X-10(X+Y)=2怎么解? y=(x^3+x)/(x^2+1)是怎么化简成y=x