(1)x(x+y)(x-y)-x(x+y)²= （2）-7m（m-n)³+21mn(n-m)²

来源：学生作业帮助网编辑：作业帮时间：2024/11/16 14:40:28

(1)x(x+y)(x-y)-x(x+y)²= （2）-7m（m-n)³+21mn(n-m)²
(1)x(x+y)(x-y)-x(x+y)²= （2）-7m（m-n)³+21mn(n-m)²

(1)x(x+y)(x-y)-x(x+y)²= （2）-7m（m-n)³+21mn(n-m)²
(1)x(x+y)(x-y)-x(x+y)²
　　= x(x+y)﹙x-y－x-y﹚
　　＝-2xy(x+y)
　　（2）-7m（m-n)³+21mn(n-m)²
　　＝－7m（m-n)²﹙m-n＋3n﹚
　　＝－7m（m-n)²﹙m+2n﹚

(1)x(x+y)(x-y)-x(x+y)²
= x(x+y)(x-y-x-y)
=-2xy(x+y)

（2）-7m（m-n)³+21mn(n-m)²
=7m(n-m)³+21mn(n-m)²
=7m(n-m)²(n-m+3n)
=7m(n-m)²(4n-m)

x(x＋y)(x－y)－x(x＋y)²
＝x³－xy²－x³－2x²y－xy²
＝-2xy²－2x²y
＝-2xy(y＋x)
-7m(m－n)³＋21mn(n－m)²＝7m(m－n)²(4n－m)

{(x,y) |x|+|y| x>y?x:y (x+y)(x-y)+4(y-1) x^/y-x-y^/y-x化简. 化简x(y-x)-y(x-y) 行列式计算 x y x+y y x+y x x+y x y|x y x+y ||y x+y x ||x+y x y | y/(x+y)-x/(x-y) x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 因式分解x(x+y)(x-y)-x(x+y)^2 x(x+y)(x-y)-x(x+y)的平方 x(x+y)(x-y)-x(x+y)² 因式分解 x y x+yy x+y xx+y x y (3x-y)(3y+x)-(x-y)(x+y) 化简x/y(x+y)-y/x(x+y) 化简 x / y(x+y) - y / x(x+y) = 化简:(x+ y)(x-y) +(x+ y) +(x-y) x+y (x+y)