Question

谁帮我解决两道初中数学因式分解题

1.3a(a-b)+b(b-a)
2.6(x-y)的立方-3y(y-x)²
3.x(x-y)(a-b)-y(y-x)(b-a)
要过程 谢谢！

Answer 1

1.3a(a-b)+b(b-a) ＝3a(a-b)－b(a-b)＝﹙a－b﹚﹙3a－b﹚
2.6(x-y)的立方-3y(y-x)²＝6﹙x－y﹚³－3y﹙x－y﹚²＝3﹙x－y﹚²﹙2－y﹚
3.x(x-y)(a-b)-y(y-x)(b-a)＝x(x-y)(a-b)-y(x-y)(a-b)＝(x-y)(a-b)﹙x－y﹚＝﹙x－y﹚²﹙a－b﹚

Answer 2

3a(a-b)+b(b-a)
=3a(a-b)-b(a-b)
=(a-b) (3a-b)

6(x-y)3-3y(y-x)²
=-6(y-x)3-3y(y-x)²
=(y-x)²(6x-6y-3y)
=(y-x)²(6x-9y)

.x(x-y)(a-b)-y(y-x)(b-a)
=.x(x-y)(a-b)-y(x-y)(a-b)
=.(x-y)²(a-b)

Answer 3

1.3a(a-b)+b(b-a)=3a(a-b)-b(a-b)=(a-b)(3a-b)
2.6(x-y)³-3y(y-x)²=6(x-y)³-3y(x-y)²=3(x-y)²[2(x-y)-y]=3(x-y)²(2x-3y)
3.x(x-y)(a-b)-y(y-x)(b-a)=x(x-y)(a-b)-y(x-y)(a-b)=(x-y)(a-b)(x-y)=(x-y)²(a-b)

Answer 4

1.3a(a-b)+b(b-a)=3a（a-b）-b（a-b）=（3a-b）（a-b）
2.6(x-y)的立方-3y(y-x)²=6（x-y）的立方-3y(x-y)²=(x-y)²（6x-6y-3y）=3（x-y）（x-y）（2x-3y）
3.x(x-y)(a-b)-y(y-x)(b-a)=x(x-y)(a-b)-y(x-y)(a-b)==0

Answer 5

1.3a(a-b)-b(a-b)=(a-b)(3a-b)
2.6﹙x－y﹚³－3y﹙x－y﹚²＝3﹙x－y﹚²﹙2－y﹚
3.x(x-y)(a-b)-y(x-y)(a-b)＝(x-y)(a-b)﹙x－y﹚＝﹙x－y﹚²﹙a－b﹚

Answer 6

三次捞出鱼的总条数是40 25 35=100（条——
三次捞出鱼的总重量是40*2.5 25*2.2 35*2.8=253（kg）
三次捞出鱼的平均重量是253 /100=2.53(kg/条）
鱼苗10万，成活率为95％
所以总重大约是100000*95%*2.53=240350（kg）
所以估计鱼塘中鱼的总重量约是240350kg.