Question

下面问题补充 帮我答其中5题就行了 可以多点就多点 要序号~ 我要看格式和方法 重悬赏

3．3ab-4ab+8ab-7ab+ab=______．

4．7x-(5x-5y)-y=______．

5．23a3bc2-15ab2c+8abc-24a3bc2-8abc=______．

6．-7x2+6x+13x2-4x-5x2=______．

7．2y+(-2y+5)-(3y+2)＝______．

11．(2x2-3xy+4y2)+(x2+2xy-3y2)=______．

12．2a-(3a-2b+2)+(3a-4b-1)=______．

13．-6x2-7x2+15x2-2x2＝______．

14．2x-(x+3y)-(-x-y)-(x-y)＝______．

16．2x+2y-[3x-2(x-y)]=______．

17．5-(1-x)-1-(x-1)=______．

18．( )+(4xy+7x2-y2)=10x2-xy．

19．(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3．

21．已知A=x3-2x2+x-4，B=2x3-5x+3，计算A+B=______．

22．已知A=x3-2x2+x-4，B=2x3-5x+3，计算A-B=______．

23．若a=-0.2，b=0.5，代数式-(|a2b|-|ab2|)的值为______．

25．一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1，那么这个多项式等于______．

26．-(2x2-y2)-[2y2-(x2+2xy)]=______．

27．若-3a3b2与5ax-1by+2是同类项，则x=______，y=______．

28．(-y+6+3y4-y3)-(2y2-3y3+y4-7)＝______．

29．化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______．

30．2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( )．

31．3a-(2a-3b)+3(a-2b)-b=______．

32．化简代数式x-[y-2x-(x+y)]等于______．

33．[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1．

34．3x-[y-(2x+y)]=______．

35．化简|1-x+y|-|x-y|(其中x＜0，y＞0)等于______．

36．已知x≤y，x+y-|x-y|=______．

37．已知x＜0，y＜0，化简|x+y|-|5-x-y|=______．

38．4a2n-an-(3an-2a2n)＝______．

39．若一个多项式加上-3x2y+2x2-3xy-4得

2x2y+3xy2-x2+2xy，

则这个多项式为______．

40．-5xm-xm-(-7xm)+(-3xm)=______．

41．当a=-1，b=-2时，

[a-(b-c)]-[-b-(-c-a)]＝______．

43．当a=-1，b=1，c=-1时，

-[b-2(-5a)]-(-3b+5c)＝______．

44．-2(3x+z)-(-6x)+(-5y+3z)=______．

45．-5an-an+1-(-7an+1)+(-3an)＝______．

46．3a-(2a-4b-6c)+3(-2c+2b)=______．

48．9a2+[7a2-2a-(-a2+3a)]=______．

50．当2y-x=5时，5(x-2y)2-3(-x+2y)-100=______．赞同53| 评论
最好要解释 ~ 求解释！

Answer 1

如果把那些有可能作为乘号的当做x时，答案如下，小孩，你也太偷懒了！！！
3.ab
4.2x+4y
5.-33 a b c
6.4x
7.3-3y
11.6x+2y-x y
12.2a-3
13.0
14.x-y
16.x
17.4
18.6x-5x y+2y
19.-3x-3y
21.x-1
22.-7-x
23.0
25.-14m+4
26.-2(x+y-x y)
27.a b(像4y与5y，100ab与14ab这样，所含字母相同，并且相同字母的次项的指数也相同的项叫做同类项)只要有a b就行
28.13+9y
29.3-x
30.c-2b 2b-c 2b-2a+3d
31.4a
32.6x
33.2 1 8
34.5x
35.1
36.2x
37.-5
38.8an
39.21x y-6x+4
40.-2x m
41.0
43.17
44.z-5y
45.-2an
46.a+2b
48.29a
50.-165
不懂得问我。看得懂就不用问了。说实话看的好累
加油了小学妹

Answer 2

3．3ab-4ab+8ab-7ab+ab=(3-4+8-7+1)ab=ab
4．7x-(5x-5y)-y=7x-5x+5y-y=(7-5)x+(5-1)y=2x+4y
31．3a-(2a-3b)+3(a-2b)-b=3a-2a+3b+3a-6b=(3-2+3)a+(3-6)b=4a-3b
32．化简代数式x-[y-2x-(x+y)]等于______． x-[y-2x-(x+y)]=x-[y-2x-x-y]=x-[-3x]=x+3x=4x
34．3x-[y-(2x+y)]=3x-[y-2x-y]=3x-[-2x]=3x+2x=5x

Answer 3

3.3ab-4ab+8ab-7ab+ab=ab
4.2x+4y
5.-a3bc2-15ab2c
6.x2+2x(是不是-7x的平方阿)
7.3-3y
11.3x2-xy+y2
21.3x2-xy+y2
........

Answer 4

3．3ab-4ab+8ab-7ab+ab=12ab-9ab=3ab
4. 7x-(5x-5y)-y=7x-5x+5y+y=2X+6y
5.23a3bc2-15ab2c+8abc-24a3bc2-8abc=23a3bc2-24a3bc2+(-15ab2c)+(8abc-8abc)=-a3bc2-15ab2c
6.看不清楚是X还是乘以
7.2y+(-2y+5)-(3y+2)＝7-3y
12..2a-(3a-2b+2)+(3a-4b-1)=2a+2b-4b-1=2a-2b-1

Answer 5

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