2X+3Y=14 3X+2Y=15 不把方程组解出来,求X+Y=有助于回答者给出准确的答案

2X+3Y=14 3X+2Y=15 不把方程组解出来,求X+Y=有助于回答者给出准确的答案 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 (5)若x/2=y/3(y不为0）则x/y=____,x+y/y=___,y/x-y=___. 把(x-y)看做一个整体,合并同类项5(x-y)+2(x-y)-4(x-y)=3(x-y)次方-4(x-y)+7(x-y)-6(x-y)次方= (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)=? 把下列各式分解因式 x(x+y)(x-y)-x(y+x)² 2 已知2x+y=6,x-3y=1,求7y（x-3y）²把下列各式分解因式x(x+y)(x-y)-x(y+x)²7、已知2x+y=6,x-3y=1,求7y（x-3y）²-2（3y-x）³的值 把6x（x－y）的平方＋3（y－x）的立方分解因式我知道答案是6x(x-y)^2+3(y-x)^3=6x(x-y)^2-3(x-y)^3=3(x-y)^2[2x-(x-y)]=3(x-y)^2(x+y)可为什么=6x(x-y)^2-3(x-y)^3=3(x-y)^2[2x-(x-y)] 把x^4+2x^2y^2+y^4-2x^3y-2xy^3分解因式x=14、y=13时的值 【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-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值