1,(x+y-z)(x-y+z)-(y+z-x)(z-x-y)=(x+y-z)(x-y+z)+(y+z-x)(x+y-z)=(x+y-z)(x-y+z+y+z-x)=2z(x+y-z)2,2xy+3 y²=y(2x+3y)x方+2xy+y方=(x+y)² 不能用提公因式法3,ax-bx=x(a-b)与 by-ay=-y(a-b) 有公因式... 解析看不懂?免费查看同类题视频...