急求50道初一數學化簡求值題有答案的

2021-03-07 04:14:52 字數 10551 閱讀 4203

1樓:匿名使用者

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,計算a+b=______.

22.已知a=x3-2x2+x-4,b=2x3-5x+3,計算a-b=______.

23.若a=-0.2,b=0.5,代數式-(|a2b|-|ab2|)的值為______.

25.一個多項式減去3m4-m3-2m+5得-2m4-3m3-2m2-1,那麼這個多項式等於______.

26.-(2x2-y2)-[2y2-(x2+2xy)]=______.

27.若-3a3b2與5ax-1by+2是同類項,則x=______,y=______.

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

29.化簡代數式4x2-[7x2-5x-3(1-2x+x2)]的結果是______.

30.2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).

31.3a-(2a-3b)+3(a-2b)-b=______.

32.化簡代數式x-[y-2x-(x+y)]等於______.

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

34.3x-[y-(2x+y)]=______.

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

36.已知x≤y,x+y-|x-y|=______.

37.已知x<0,y<0,化簡|x+y|-|5-x-y|=______.

38.4a2n-an-(3an-2a2n)=______.

39.若一個多項式加上-3x2y+2x2-3xy-4得

2x2y+3xy2-x2+2xy,

則這個多項式為______.

40.-5xm-xm-(-7xm)+(-3xm)=______.

41.當a=-1,b=-2時,

[a-(b-c)]-[-b-(-c-a)]=______.

43.當a=-1,b=1,c=-1時,

-[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.當2y-x=5時,5(x-2y)2-3(-x+2y)-100=______.

小屁伢自幾寫

2樓:匿名使用者

(1)已知,a+b=4,ab=-2,求代數式(4a-3b-2ab)-(a-6b-ab)的值.

(2)5(3a2b-ab2)-4(-3ab2+2a2b),其中a=-2,b=3

(3)其中m=-2 n=-3 [(m-2n)²+(m-2n)(m-2n)-2m(m-n)+2m³]/2m c)(a-b+c)-c(a+b)

(4)已知(ab+1)2+|a+b-2|=0,先化簡再求值:(2a-b-1)-(a+2b)(a-b).

(5):(3x+2)(3x-2)-5x(x-1)-(2x-1)²,其中=-1/3

(6)已知x2-2x=2 ,先化簡再求值(x-1)2+(x+3)(x-3)+(x+3)(x-1)的值

(7) (a2+b2)(a2-b2)-(a+b)2(a-b)2,其中a=4,b=1

(8)8m-(6m2+15m2n)/3m+m(n-1),其中m=2,n=1

(9)(a-2b)²-a(a-b)+2ab,其中a=1/2,b=1

(10)[(x-y)2+(x+y)(x-y)]·2x其中x=3 y=-1.5

(11) 6m2-5m(-m+2n-1)+4m(-3m-5/2n-3/4),其中m=-1,n=2.

(12)(4x2y-5y2x)-(3x2y-4xy2),其中x=--1,y=2\1

(13)(x-3)2-x(x-8),其中x=2-4

(14) (x+y)(x-y)+(x-y)²-(6x²y-2xy²)÷(2xy),當x=-2,y=1/3

(15)(25a2-5a+1)(5a+1-5(1+2a)(2a-1)的值,其中a=2/5

(16)-8x2-5x(-x+3y)+(3x+2y)(x-y),其中x=2,y=-1.

(17)x(x3+x2-x+1)-(x2+x-2),其中x=-三分之二

(18)x(x-4)(x+4)-(x+3)(x2_6x+9)+(5x3y2)÷(x2y2),其中x=-3

(19)(5y+1)(5y-1)-5(y+25y2),其中y=2/5

(20)(a+b)2-(a-b)2-4ab,其中a=1998,b=1997

(21)(5b-b2+1)-(5a-a2+1) 其中a+b=5 ab= -2

(22)(3ab-a²)-[2a²-(3ab-b²)],其中a=-2,b=1

(23)(a-b)2+b(a-b)-(-a+2b)(-a-2b),其中a=2,b=-1/2

(24)4x3-[-x2+2(x3- 1/3x2)] 其中x=-3

(25)4(x+1)2-7(x-1)(x+1)+3(1-x)2 其中x=1/2

(26)(2a+)2-(2a-b)(a+b)-2(a-2b)(a+2b),其中x=-2,y=二分之一

(27)[(2a+b)²+(2a-b)²](4a²-b²),其中a=-2分之1,b=3

(28)[(2a+b)^2+(2a+b)×(b-2a)-6b]÷2b,其中a=﹣0.5,b=3

(29)[(2x-y)2-x(4x-y)+8y2]除以3y,其中x=3/4, y=-1/2.

(30)2(a²b﹢ab²)-2(a²b-1)-2ab²-2ab,其中a=1,b=﹣1

求50道初一數學化簡求值題有答案的簡單點的有答

3樓:

關於bai數學學科的學習,du從巨集觀上看我認為zhi有一個學習時間安排dao的問題,我內說的是文科數學。對於容文科同學來說,由於高三前期文科綜合的學習任務不是很重,而且在高三第二學期後期,它的記憶需要非常繁瑣而且需要佔據大部分學習時間的,所以我覺得對於數學學科要根據不同的階段來區別對待。在高三的前期,就是在高

一、高二的時候,必須給數學分配比較大的學習時間,因為在高考,不管是文科或者理科,數學都是一門拉分的科目,分配學習時間的時候,必須有所傾斜,而在高三學期的後半學期,由於文綜花在上面的時間比較合算,比較能最終提高高考分數,所以複習時間以每半個小時為宜,讓自己不至於手生,做題的時候,有非常大的敏感度,能夠保持一個反應非常快的狀態,花半個小時差不多了,不要花太多的時間,否則就會擠佔複習文綜的時間了。

求50道初一化簡求值題(急) 20

4樓:胡椒_醒目

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,計算a+b=______.

22.已知a=x3-2x2+x-4,b=2x3-5x+3,計算a-b=______.

23.若a=-0.2,b=0.5,代數式-(|a2b|-|ab2|)的值為______.

25.一個多項式減去3m4-m3-2m+5得-2m4-3m3-2m2-1,那麼這個多項式等於______.

26.-(2x2-y2)-[2y2-(x2+2xy)]=______.

27.若-3a3b2與5ax-1by+2是同類項,則x=______,y=______.

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

29.化簡代數式4x2-[7x2-5x-3(1-2x+x2)]的結果是______.

30.2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).

31.3a-(2a-3b)+3(a-2b)-b=______.

32.化簡代數式x-[y-2x-(x+y)]等於______.

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

34.3x-[y-(2x+y)]=______.

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

36.已知x≤y,x+y-|x-y|=______.

37.已知x<0,y<0,化簡|x+y|-|5-x-y|=______.

38.4a2n-an-(3an-2a2n)=______.

39.若一個多項式加上-3x2y+2x2-3xy-4得

2x2y+3xy2-x2+2xy,

則這個多項式為______.

40.-5xm-xm-(-7xm)+(-3xm)=______.

41.當a=-1,b=-2時,

[a-(b-c)]-[-b-(-c-a)]=______.

43.當a=-1,b=1,c=-1時,

-[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.當2y-x=5時,5(x-2y)2-3(-x+2y)-100=______.

(二)選擇

[ ]a.2;

b.-2;

c.-10;

d.-6.

52.下列各式中計算結果為-7x-5x2+6x3的是 [ ]

a.3x-(5x2+6x3-10x);

b.3x-(5x2+6x3+10x);

c.3x-(5x2-6x3+10x);

d.3x-(5x2-6x3-10x).

53.把(-x-y)+3(x+y)-5(x+y)合併同類項得 [ ]

a.(x-y)-2(x+y);

b.-3(x+y);

c.(-x-y)-2(x+y);

d.3(x+y).

54.2a-[3b-5a-(2a-7b)]等於 [ ]

a.-7a+10b;

b.5a+4b;

c.-a-4b;

d.9a-10b.

55.減去-3m等於5m2-3m-5的代數式是 [ ]

a.5(m2-1);

b.5m2-6m-5;

c.5(m2+1);

d.-(5m2+6m-5).

56.將多項式2ab-9a2-5ab-4a2中的同類項分別結合在一起,應為 [ ]

a.(9a2-4a2)+(-2ab-5ab);

b.(9a2+4a2)-(2ab-5ab);

c.(9a2-4a2)-(2ab+5ab);

d.(9a2-4a2)+(2ab-5ab).

57.當a=2,b=1時,-a2b+3ba2-(-2a2b)等於 [ ]

a.20;

b.24;

c.0;

d.16.

中,正確的選擇是 [ ]

a.沒有同類項;

b.(2)與(4)是同類項;

c.(2)與(5)是同類項;

d.(2)與(4)不是同類項.

59.若a和b均為五次多項式,則a-b一定是 [ ]

a.十次多項式;

b.零次多項式;

c.次數不高於五次的多項式;

d.次數低於五次的多項式.

60.-{[-(x+y)]}+{-[(x+y)]}等於 [ ]

a.0;

b.-2y;

c.x+y;

d.-2x-2y.

61.若a=3x2-5x+2,b=3x2-5x+6,則a與b的大小是

[ ]a.a>b;

b.a=b;

c.a<b;

d.無法確定.

62.當m=-1時,-2m2-[-4m2+(-m2)]等於 [ ]

a.-7;

b.3;

c.1;

d.2.

63.當m=2,n=1時,多項式-m-[-(2m-3n)]+[-(-3m)-4n]等於 [ ]

a.1;

b.9;

c.3;

d.5.

[ ]65.-5an-an-(-7an)+(-3an)等於 [ ]

a.-16an;

b.-16;

c.-2an;

d.-2.

66.(5a-3b)-3(a2-2b)等於 [ ]

a.3a2+5a+3b;

b.2a2+3b;

c.2a3-b2;

d.-3a2+5a-5b.

67.x3-5x2-4x+9等於 [ ]

a.(x3-5x2)-(-4x+9);

b.x3-5x2-(4x+9);

c.-(-x3+5x2)-(4x-9);

d.x3+9-(5x2-4x).

[ ]69.4x2y-5xy2的結果應為 [ ]

a.-x2y;

b.-1;

c.-x2y2;

d.以上答案都不對.

(三)化簡

70.(4x2-8x+5)-(x3+3x2-6x+2).

72.(0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2).

73.-{2a2b-[3abc-(4ab2-a2b)]}.

74.(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b).

75.(x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2).

76.(3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4).

77.(4a-2b-c)-5a-[8b-2c-(a+b)].

78.(2m-3n)-(3m-2n)+(5n+m).

79.(3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab).

80.xy-(2xy-3z)+(3xy-4z).

81.(-3x3+2x2-5x+1)-(5-6x-x2+x3).

83.3x-(2x-4y-6x)+3(-2z+2y).

84.(-x2+4+3x4-x3)-(x2+2x-x4-5).

85.若a=5a2-2ab+3b2,b=-2b2+3ab-a2,計算a+b.

86.已知a=3a2-5a-12,b=2a2+3a-4,求2(a-b).

87.2m-{-3n+[-4m-(3m-n)]}.

88.5m2n+(-2m2n)+2mn2-(+m2n).

89.4(x-y+z)-2(x+y-z)-3(-x-y-z).

90.2(x2-2xy+y2-3)+(-x2+y2)-(x2+2xy+y2).

92.2(a2-ab-b2)-3(4a-2b)+2(7a2-4ab+b2).

94.4x-2(x-3)-3[x-3(4-2x)+8].

(四)將下列各式先化簡,再求值

97.已知a+b=2,a-b=-1,求3(a+b)2(a-b)2-5(a+b)2×(a-b)2的值.

98.已知a=a2+2b2-3c2,b=-b2-2c2+3a2,c=c2+2a2-3b2,求(a-b)+c.

99.求(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2.

101.已知|x+1|+(y-2)2=0,求代數式5(2x-y)-3(x-4y)的值.

106.當p=a2+2ab+b2,q=a2-2ab-b2時,求p-[q-2p-(p-q)].

107.求2x2-{-3x+5+[4x2-(3x2-x-1)]}的值,其中x=-3.

110.當x=-2,y=-1,z=3時,求5xyz-{2x2y-[3xyz-(4xy2-x2y)]}的值.

113.已知a=x3-5x2,b=x2-6x+3,求a-3(-2b).

(五)綜合練習

115.去括號:{-[-(a+b)]}-{-[-(a-b)]}.

116.去括號:-[-(-x)-y]-[+(-y)-(+x)].

117.已知a=x3+6x-9,b=-x3-2x2+4x-6,計算2a-3b,並把結果放在前面帶「-」號的括號內.

118.計算下式,並把結果放在前面帶「-」號的括號內:

(-7y2)+(-4y)-(-y2)-(+5y)+(-8y2)+(+3y).

119.去括號、合併同類項,將結果按x的升冪排列,並把後三項放在帶有「-」號的括號內:

120.不改變下式的值,將其中各括號前的符號都變成相反的符號:(x3+3x2)-(3x2y-7xy)+(2y3-3y2).

121.把多項式4x2y-2xy2+4xy+6-x2y2+x3-y2的三次項放在前面帶有「-」號的括號內,二次項放在前面帶有「+」號的括號內,四次項和常數項放在前面帶有「-」號的括號內.

122.把下列多項式的括號去掉,合併同類項,並將其各項放在前面帶有「-」號的括號內,再求2x-2[3x-(5x2-2x+1)]-4x2的值,其中x=-1.

123.合併同類項:

7x-1.3z-4.7-3.2x-y+2.1z+5-0.1y.

124.合併同類項:5m2n+5mn2-mn+3m2n-6mn2-8mn.

126.去括號,合併同類項:

(1)(m+1)-(-n+m);

(2)4m-[5m-(2m-1)].

127.化簡:2x2-{-3x-[4x2-(3x2-x)+(x-x2)]}.

128.化簡:-(7x-y-2z)-{[4x-(x-y-z)-3x+z]-x}.

129.計算:(+3a)+(-5a)+(-7a)+(-31a)-(+4a)-(-8a).

130.化簡:a3-(a2-a)+(a2-a+1)-(1-a4+a3).

131.將x2-8x+2x3-13x2-2x-2x3+3先合併同類項,再求值,其中x=-4.

132.在括號內填上適當的項:[( )-9y+( )]+2y2+3y-4=11y2-( )+13.

133.在括號內填上適當的項:

(-x+y+z)(x+y-z)=[y-( )][y+( )].

134.在括號內填上適當的項:

(3x2+xy-7y2)-( )=y2-2xy-x2.

135.在括號內填上適當的項:

(1)x2-xy+y-1=x2-( );

(2)[( )+6x-7]-[4x2+( )-( )]=x2-2x+1.

136.計算4x2-3[x+4(1-x)-x2]-2(4x2-1)的值.

137.化簡:

138.用豎式計算

(-x+5+2x4-6x3)-(3x4+2x2-3x3-7).

139.已知a=11x3+8x2-6x+2,b=7x3-x2+x+3,求2(3a-2b).

140.已知a=x3-5x2,b=x3-11x+6,c=4x-3,求

(1)a-b-c;

(2)(a-b-c)-(a-b+c).

141.已知a=3x2-4x3,b=x3-5x2+2,計算

(1)a+b;

(2)b-a.

142.已知x<-4,化簡|-x|+|x+4|-|x-4|.

146.求兩代數式-1.56a+3.2a3-0.

47,2.27a3-0.02a2+4.

03a+0.53的差與6-0.15a+3.

24a2+5.07a3的和.

-0.3,y=-0.2.

150.已知(x-3)2+|y+1|+z2=0,求x2-2xy-5x2+12xz+3xy-z2-8xz-2x2的值.

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設甲種存款x萬元,則乙種存款為 30 x 萬元得方程為 2.5 x 2.25 30 x 0.715解得x 16萬元,所以甲種存款16萬元,乙種存款14萬元。設甲存款x萬元,則乙30 x 有0.025 x 10000 30 x 10000 0.0225 7150 得x 8 30 8 32 設甲存x萬元...

請教一道初一數學題!急求

解 2x 4m 5 2m 移項 2x 2m 5 x m 5 2 因為 x 0 m 5 2 0 m 2.5 2x 4m 5 2m 2x 2m 5 x m 2.5 m 2.5 0 m 2.5 x y 1 x y 2 1 x 2 y 2 2xy 1 2xy 1 xy 1 2 x y x 2 y 2 x 3...