初二数学来自计算题附带答案
的有关信息介绍如下:问题补充说明:一次二次方程也可以 求帮忙
氢上资①5√8-2√32+√5360问答0
=5*3√2-2*4√2+5√2
=√2市岩举海(15-8+5)
=12√2
②√6-√3/2-√2/3
=√6-√6/2-√6/3
=√6/6
③(√45+√27)-(√4/3+√125)
=(3√5+3√3)-(2√3/3+5√5)
=-2√5+7√5/3
④(√4a-√50b)-2(√b/2+√9a)
=(2√a-5√2b)-2(√2b/2+3√a)
=-4√a-6√2b
⑤√4x*(√3x/2-√x/6)
=2√x(√6x/2-√6x/6)
=2√x*(√6周记零社x/3)
=2/3*齐周春觉重|x|*√6
⑥(x√y-y√x)÷√xy
=x√y÷√xy-y√x÷√xy
=√x-√y
⑦(3√7+2√3)(2√3-3√7)
=(2√3)^2-(3√7)^2
=12-选达来63
=-51
⑧(√32-3√3)(4√2+√27)
=(4√2-3√3)(4√2+3√3)
=(4√2)^2-(3√3)^2
=32-27
=5
⑨(3√6-√没编武省念面费烧4)?
=(3√6问宗)^2-2*3√6*√4+(物传支源黄啊企属维希√4)^2
=54-12√6+4
=58-12√6
⑩(下巴需余地调动轻间湖1+√2-√3)(1-√2+√3)
=[1+(√2-√3)][1-(√2-√3)]
=1-(√2-成停坐精√3)^2
=1-(2+3+2√6)
=-4-茶著会掌第杂外攻证广2√6
(1)5√12×√18
=5*2√3*3√2
=30√6;
(2)-6√45×(-4√48)
=6*3√只练红又复读感命鲜话没5*4*4√3
=288√15;
(3)√(12a)×√(3a)/4
=√(36a^2)/切坐培目宪读菜次卷措搞4
=6a/4
=3a/2.
5.
x^2(y+z)^2-2xy(x-z)(y+z)+y^2(x-z)^2
=[x(y+z)-y(x-z)]^2
=(xz+yz)^2
=z^2(x+y)^2
6.
3(a+2)^2+28(a越阻它诗钟乙面+2)-20
=[3(a+2)-2][(a+2)+10]
=(3a+4)(a+12)
7.
(a+投联米达球记改运b)^2-(b-c)^2+a^2-c^2
=(a+b)^2仍独凯孙其转活术全-c^2+a^2-(b-c)^2
=(a+b+c)(a+b-c)+(a+b-c)(a-b+c)
=(a+b-c)(a+b+c+a-b+c)
=2(a+b-c)(a+c)
8.
x(x+1)(x^2+x-1)-2
=(x^2+x)(x^2+x-1)-2
=(x^2+x)^2-(x^2+x)-2
=(x^2+x-2)(x^2+x+1)
=(x+2)(x-1)(x^2+x+1)
9.
9x^2(x-1)^2-3(x^2-x)-56
=9x^2(x-1)^2-3x(x-1)-56
=[3x(x-1)-8][3x(x-1)+7]
=(3x^2-3x-8)(3x^2-3x+7)
有理数练习
练习一(B级)
(一)计算题:
(1)23+(-73)(2)(-84)+(-49)(3)7+(-2.04)(4)4.23+(-7.57)(5)(-7/3)+(-7/6)(6)9/4+(-3/2)(7)3.75+(2.25)+5/4(8)-3.75+(+5/4)+(-1.5)
5.
x^2(y+z)^2-2xy(x-z)(y+z)+y^2(x-z)^2
=[x(y+z)-y(x-z)]^2
=(xz+yz)^2
=z^2(x+y)^2
6.
3(a+2)^2+28(a+2)-20
=[3(a+2)-2][(a+2)+10]
=(3a+4)(a+12)
7.
(a+b)^2-(b-c)^2+a^2-c^2
=(a+b)^2-c^2+a^2-(b-c)^2
=(a+b+c)(a+b-c)+(a+b-c)(a-b+c)
=(a+b-c)(a+b+c+a-b+c)
=2(a+b-c)(a+c)
8.
x(x+1)(x^2+x-1)-2
=(x^2+x)(x^2+x-1)-2
=(x^2+x)^2-(x^2+x)-2
=(x^2+x-2)(x^2+x+1)
=(x+2)(x-1)(x^2+x+1)
9.
9x^2(x-1)^2-3(x^2-x)-56
=9x^2(x-1)^2-3x(x-1)-56
=[3x(x-1)-8][3x(x-1)+7]
=(3x^2-3x-8)(3x^2-3x+7)
1.125*3+125*5+25*3+25
2.9999*3+101*11*(101-92)
3.(23/4-3/4)*(3*6+2)
4.3/7×49/9-4/3
5.8/9×15/36+1/27
6.12×5/6–2/9×3
7.8×5/4+1/4
8.6÷3/8–3/8÷6
9.4/7×5/9+3/7×5/9
10.5/2-(3/2+4/5)
11.7/8+(1/8+1/9)
12.9×5/6+5/6
13.3/4×8/9-1/3
14.7×5/49+3/14
15.6×(1/2+2/3)
16.8×4/5+8×11/5
17.31×5/6–5/6
18.9/7-(2/7–10/21)
19.5/9×18–14×2/7
20.4/5×25/16+2/3×3/4
21.14×8/7–5/6×12/15
22.17/32–3/4×9/24
23.3×2/9+1/3
24.5/7×3/25+3/7
25.3/14××2/3+1/6
26.1/5×2/3+5/6
27.9/22+1/11÷1/2
28.5/3×11/5+4/3
29.45×2/3+1/3×15
30.7/19+12/19×5/6
31.1/4+3/4÷2/3
32.8/7×21/16+1/2
33.101×1/5–1/5×21
34.50+160÷40
35.120-144÷18+35
36.347+45×2-4160÷52
37(58+37)÷(64-9×5)
38.95÷(64-45)
39.178-145÷5×6+42
40.812-700÷(9+31×11)
41.85+14×(14+208÷26)
43.120-36×4÷18+35
44.(58+37)÷(64-9×5)
45.(6.8-6.8×0.55)÷8.5
46.0.12×4.8÷0.12×4.8
47.(3.2×1.5+2.5)÷1.6
48.6-1.6÷4=5.38+7.85-5.37=
49.7.2÷0.8-1.2×5=6-1.19×3-0.43=
50.6.5×(4.8-1.2×4)=
51.5.8×(3.87-0.13)+4.2×3.74
52.32.52-(6+9.728÷3.2)×2.5
53.[(7.1-5.6)×0.9-1.15]÷2.5
54.5.4÷[2.6×(3.7-2.9)+0.62]
55.12×6÷(12-7.2)-6
56.12×6÷7.2-6
57.0.68×1.9+0.32×1.9
58.58+370)÷(64-45)
59.420+580-64×21÷28
60.136+6×(65-345÷23)
15-10.75×0.4-5.7
62.18.1+(3-0.299÷0.23)×1
63.(6.8-6.8×0.55)÷8.5
64.0.12×4.8÷0.12×4.8
65.(3.2×1.5+2.5)÷1.6
66.3.2×6+(1.5+2.5)÷1.6
67.0.68×1.9+0.32×1.9
68.10.15-10.75×0.4-5.7
69.5.8×(3.87-0.13)+4.2×3.74
70.32.52-(6+9.728÷3.2)×2.5
71.[(7.1-5.6)×0.9-1.15]÷2.5
72.5.4÷[2.6×(3.7-2.9)+0.62]
73.12×6÷(12-7.2)-6
74.12×6÷7.2-6
75.33.02-(148.4-90.85)÷2.5
1)76.(25%-695%-12%)*36
77./4*3/5+3/4*2/5
78.1-1/4+8/9/7/9
79.+1/6/3/24+2/21
80./15*3/5
81.3/4/9/10-1/6
82./3+1/2)/5/6-1/3]/1/7
83./5+3/5/2+3/4
84.(2-2/3/1/2)]*2/5
85.+5268.32-2569
86.3+456-52*8
87.5%+6325
88./2+1/3+1/4
2)89+456-78
3)5%+.3/7×49/9-4/3
4)9×15/36+1/27
5)2×5/6–2/9×3
6)3×5/4+1/4
7)94÷3/8–3/8÷6
8)95/7×5/9+3/7×5/9
9)6/2-(3/2+4/5)
10)8+(1/8+1/9)
11)8×5/6+5/6
12)1/4×8/9-1/3
13)10×5/49+3/14
14)1.5×(1/2+2/3)
15)2/9×4/5+8×11/5
16)3.1×5/6–5/6
17)4/7-(2/7–10/21)
18)19×18–14×2/7
19)5×25/16+2/3×3/4
20)4×8/7–5/6×12/15
21)7/32–3/4×9/24
22)1、2/3÷1/2-1/4×2/5
2、2-6/13÷9/26-2/3
3、2/9+1/2÷4/5+3/8
4、10÷5/9+1/6×4
5、1/2×2/5+9/10÷9/20
6、5/9×3/10+2/7÷2/5
7、1/2+1/4×4/5-1/8
8、3/4×5/7×4/3-1/2
9、23-8/9×1/27÷1/27
10、8×5/6+2/5÷4
11、1/2+3/4×5/12×4/5
12、8/9×3/4-3/8÷3/4
13、5/8÷5/4+3/23÷9/11
23)1.2×2.5+0.8×2.5
24)8.9×1.25-0.9×1.25
25)12.5×7.4×0.8
26)9.9×6.4-(2.5+0.24)(27)6.5×9.5+6.5×0.5
0.35×1.6+0.35×3.4
0.25×8.6×4
6.72-3.28-1.72
0.45+6.37+4.55
5.4+6.9×3-(25-2.5)2×41846-620-380
4.8×46+4.8×54
0.8+0.8×2.5
1.25×3.6×8×2.5-12.5×2.4
28×12.5-12.5×20
23.65-(3.07+3.65)
(4+0.4×0.25)8×7×1.25
1.65×99+1.65
27.85-(7.85+3.4)
48×1.25+50×1.25×0.2×8
7.8×9.9+0.78
(1010+309+4+681+6)×12
3×9146×782×6×854
5.15×7/8+6.1-0.60625
1.3/7×49/9-4/3
2.8/9×15/36+1/27
3.12×5/6–2/9×3
4.8×5/4+1/4
5.6÷3/8–3/8÷6
6.4/7×5/9+3/7×5/9
7.5/2-(3/2+4/5)
8.7/8+(1/8+1/9)
9.9×5/6+5/6
10.3/4×8/9-1/3
11.7×5/49+3/14
12.6×(1/2+2/3)
13.8×4/5+8×11/5
14.31×5/6–5/6
15.9/7-(2/7–10/21)
16.5/9×18–14×2/7
17.4/5×25/16+2/3×3/4
18.14×8/7–5/6×12/15
19.17/32–3/4×9/24
20.3×2/9+1/3
21.5/7×3/25+3/7
22.3/14××2/3+1/6
23.1/5×2/3+5/6
24.9/22+1/11÷1/2
25.5/3×11/5+4/3
26.45×2/3+1/3×15
27.7/19+12/19×5/6
28.1/4+3/4÷2/3
29.8/7×21/16+1/2
30.101×1/5–1/5×21
31.50+160÷40(58+370)÷(64-45)
32.120-144÷18+35
33.347+45×2-4160÷52
34(58+37)÷(64-9×5)
35.95÷(64-45)
36.178-145÷5×6+42420+580-64×21÷28
37.812-700÷(9+31×11)(136+64)×(65-345÷23)
38.85+14×(14+208÷26)
39.(284+16)×(512-8208÷18)
40.120-36×4÷18+35
41.(58+37)÷(64-9×5)
42.(6.8-6.8×0.55)÷8.5
43.0.12×4.8÷0.12×4.8
44.(3.2×1.5+2.5)÷1.6(2)3.2×(1.5+2.5)÷1.6
45.6-1.6÷4=5.38+7.85-5.37=
46.7.2÷0.8-1.2×5=6-1.19×3-0.43=
47.6.5×(4.8-1.2×4)=0.68×1.9+0.32×1.9
48.10.15-10.75×0.4-5.7
49.5.8×(3.87-0.13)+4.2×3.74
50.32.52-(6+9.728÷3.2)×2.5
51.[(7.1-5.6)×0.9-1.15]÷2.5
52.5.4÷[2.6×(3.7-2.9)+0.62]
53.12×6÷(12-7.2)-6(4)12×6÷7.2-6
102×4.5
7.8×6.9+2.2×6.9
5.6×0.25
8×(20-1.25)
1)127+352+73+44(2)89+276+135+33
(1)25+71+75+29+88(2)243+89+111+57
9405-2940÷28×21
920-1680÷40÷7
690+47×52-398
148+3328÷64-75
360×24÷32+730
2100-94+48×54
51+(2304-2042)×23
4215+(4361-716)÷81
(247+18)×27÷25
36-720÷(360÷18)
1080÷(63-54)×80
(528+912)×5-6178
8528÷41×38-904
264+318-8280÷69
(174+209)×26-9000
814-(278+322)÷15
1406+735×9÷45
3168-7828÷38+504
796-5040÷(630÷7)
285+(3000-372)÷36
1+5/6-19/12
3x(-9)+7x(-9
(-54)x1/6x(-1/3)
1.18.1+(3-0.299÷0.23)×1
2.(6.8-6.8×0.55)÷8.5
3.0.12×4.8÷0.12×4.8
4.(3.2×1.5+2.5)÷1.6(2)3.2×(1.5+2.5)÷1.6
5.6-1.6÷4=5.38+7.85-5.37=
6.7.2÷0.8-1.2×5=6-1.19×3-0.43=
7.6.5×(4.8-1.2×4)=0.68×1.9+0.32×1.9
8.10.15-10.75×0.4-5.7
9.5.8×(3.87-0.13)+4.2×3.74
10.32.52-(6+9.728÷3.2)×2.5
11.[(7.1-5.6)×0.9-1.15]÷2.5
12.5.4÷[2.6×(3.7-2.9)+0.62]
13.12×6÷(12-7.2)-6
14.12×6÷7.2-6
15.33.02-(148.4-90.85)÷2.5
7×(5/21+9/714)
a^3-2b^3+ab(2a-b)
=a^3+2a^2b-2b^3-ab^2
=a^2(a+2b)-b^2(2b+a)
=(a+2b)(a^2-b^2)
=(a+2b)(a+b)(a-b)
2.
(x^2+y^2)^2-4y(x^2+y^2)+4y^2
=(x^2+y^2-2y)^2
3.
(x^2+2x)^2+3(x^2+2x)+x^2+2x+3
=(x^2+2x)^2+4(x^2+2x)+3
=(x^2+2x+3)(x^2+2x+1)
=(x^2+2x+3)(x+1)^2
4.
(a+1)(a+2)+(2a+1)(a-2)-12
=a^2+3a+2+2a^2-3a-2-12
=3a^2-12
=3(a+2)(a-2)
5.
x^2(y+z)^2-2xy(x-z)(y+z)+y^2(x-z)^2
=[x(y+z)-y(x-z)]^2
=(xz+yz)^2
=z^2(x+y)^2
6.
3(a+2)^2+28(a+2)-20
=[3(a+2)-2][(a+2)+10]
=(3a+4)(a+12)
7.
(a+b)^2-(b-c)^2+a^2-c^2
=(a+b)^2-c^2+a^2-(b-c)^2
=(a+b+c)(a+b-c)+(a+b-c)(a-b+c)
=(a+b-c)(a+b+c+a-b+c)
=2(a+b-c)(a+c)
8.
x(x+1)(x^2+x-1)-2
=(x^2+x)(x^2+x-1)-2
=(x^2+x)^2-(x^2+x)-2
=(x^2+x-2)(x^2+x+1)
=(x+2)(x-1)(x^2+x+1)
写完一遍后再别这些题写一遍,以此类推,老师们看作业都是一看而过不会一个一个批的。