1、人教版数学七年级上册期末计算题100例附解析(5)1.计算:(-4)-(-1)+(-6)2 2.3x2y25xy2(4xy23)+2x2y2 3.计算: 34(27)(2)(43)+(2)3 4.解方程 (1)5x+3(2x)=8 (2)x32 4x+15 =1 5.计算 (1)812+2 (2)18+(7.5)(31)12.5 (3) 18 (+1 13 )( 58 )(+4 23 ) (4)1(1)( 37 )(+5)( 47 )+|4| 6. (1)计算:42( 1312 ) 16 (2)2; (2)化简:(4x3y)(3yx)+(xy)5x 7.如果方程3(x1)2(x+1)=3和 2
2、x13x+a2=1 的解相同,求出a的值 8.解方程 (1)10x+7=12x5 (2)3x141=5x76 9. 解下列关于x的一元一次方程: (1)3x+7=32-2x (2)x3=32x+1 10.解方程:4x-4=12+2x 11.计算: (1)5+(-6) (2)(-7)-(-8) 12.解方程 (1)3(x1)+62(x+3)+7 (2)1+ x2 82x3 13.解方程: (1)3(2x+3)=11x-6; (2)3x-6(x-1)=3-2(x+3) 14.先化简,再求值: x2y+xy23(xy213x2y) ,其中 x=12 , y=1 . 15.已知:A=8xyx2+y2,
3、B=x2y2+8xy求:(1) A+B(2)2A-3B16.4x3(20x)4 17.化简 (1)(x32y33x2y)(x33y34x2y) ; (2)5(2x7y)3(4x10y) 18.阅读下面文字: 对于(5 56 )+(9 23 )+17 34 +(3 12 )可以如下计算:原式=(5)+( 56 )+(9)+( 23 )+(17+ 34 )+(3)+( 12 )=(一5)+(9)+17+(一3)+( 56 )+( 23 )+ 34 +( 12 )=0+(1 14 )=1 14 上面这种方法叫拆项法,你看懂了吗?仿照上面的方法,请你计算:(1 12 )+(2000 56 )+4000
4、 34 +(1999 23 )19.计算: (12)2+34(2+3|32|)20.计算题: (1)10(5)+(9)+6 (2)14+(2)(16)|3| 21.计算: (1)(+6)+(9) ; (2)(13)25 ; (3)|314+413|516 . 22.解方程: 2x35x24=1. 23.解下列方程: (1)0.5 x 0.76.51.3 x; (2)2x12=6x751 ; 24.解下列方程: (1)13(x2)=x5 ; (2)2x133x6=1 . 25.计算: (1)47(225)3751253(4) (2)4216(2) 12 (1)2019. 26.方程23(x+1)
5、=0的解与关于x的方程 k+x23k2=2x 的解互为倒数,求k的值 27.关于x的方程:(1m)x| m |20是一元一次方程求m的值和方程的解 28.计算: (1)(6)2(2312)23 (2)364+16(2)2 29.解下列方程: (1)4 x 32( x 1)1 (2)0.5x0.7=6.51.3x 30.计算: (1)255445(32) ; (2)14(10.5)23+(3)2 . 31.解方程:(1)0.5x+0.6=61.3x(2)1+y13=2y+15 32.计算:13(7)+(30)+533.计算: (1)4639+5741; (2)90772932; (3)31175
6、; (4)176523(精确到分) 34.计算 (1)1381332-23(-6)-22+|-12| (2)(-2)318+(23-12-14)112+(-1)10 35.解方程:(1)x12(3x2)=2(5x)(2)3t12=t+14 36.计算: (1)12(18)+(7)15 (2)22+|58|+27(3) 13 37. 计算: (1)2317(7)(16); (2)32 (15) 1 13 ; (3)(26.54)(6.4)18.546.4; (4)(478) (512) (414) 3 18 ; (5)(2.4)(4.7)(0.5)|2.4|(3.2) 38.计算: (1)12-
7、(-8)+(-7)-15 (2)122345+3122 39.计算:(1)179721854(2)3607(精确到秒)40.已知 0.5mxn3 与 5m4ny 是同类项,求(5x2y4x2y+3x2)(2x35x2y3y32x2y) 的值41.计算: (1)11+(9)(3) (2)14+12(12)213+16 42.计算: (1)( 12 - 13 )(- 16 )+(-2)2(-14); (2)-14-1-(1-0.5 13 )6. 43.解方程 (1)5(1x)= 4x+2 (2)x25+x3=1 44.计算 (1)(93)(2)2 (2)35(21)(23) 45.计算: (1)(
8、12)5+(14)(39) (2)(2131316)78 (3)42(112)3296(23)2 (4)1232(13)2+0.7(116) 46.计算. 4(6)(4)20 47.计算: (1)4839+6731 (2)22361822 (3)21175 (4)143164 48.计算:27(-3)2- (- 12 )(-8) 49.2(a2b2)+3ab2a2+2b22ab 50.计算 (1)18+6+75 (2)2223(1)3. 51.解方程: (1)6x+2(2-2x)=-2 (2)2x14=1x+23 52.计算: (1)5-(4-7) (2)(-2)2( 12-34 ) 53.计
9、算: (2)4(83)2+32(16)0.25 54.解下列方程: (1)3(x1)x=1(2x1) (2)x13x+26=4x2+1 . 55.已知 |ab+2|+|a+1|=0 ,求下列式子的值: 1(a1)(b+1)+1(a2)(b+2)+1(a2018)(b+2018) 56.计算: (1)(1)2+(12)15(2019)0 (2)(yx)2n(yx)3 (3)(5x3y23x2y3)(xy)3x(2xyy2) 57.先化简,再求值:2x+7+3x2,其中x=258.若a+12与-8+b互为相反数,求a与b的和. 59.解方程: (1)4x1=3x+2 (2)5x12 =1- x+1
10、4 60.计算题(1)5.6+4.4+(8.1)(2)(7)+(4)+(+9)+(5)61.计算:(3)2+15( 13 25 )+(2)3 62.计算 (1)(ab2(2a3b)3 (2)(3a2b)(3a22ab+4b2) (3)(6x44x3+2x2)(2x2) (4)(x5)(2x+5)2x(x3) 63.已知|a1|=4,|2b|=5,求ab的值64.计算: (1)3-(-2)+(-4); (2)12x( 2312 )-(-2)3 65. 计算: (1)1(2)+(3)+(4)(5) ; (2)18+1558+25 ; (3)(479)(316)(+229)+(616) 66.2.7
11、(3.3) 67.解方程: (1)3x-7(x-1)=5-2(x+ 3); (2)x- x12 =2- x+185 68.解方程: (1)3x=-9x-12 (2)2(3y5)=3(1y)+1 (3)x22=42x3 (4)5x+46x=3x24 69.解下列方程或方程组: (1)3x-(x-5)=2(2x-1); (2)y+282y16=1 ; (3)2x3y=53x+2y=12 ; (4)x+13=y12+1623x+y2=53 . 70.已知:|a|=2,|b|=3,且a+b0,求a+b的值71.阅读下列内容,然后解答问题: 因为: 112=112,123=1213,134=131419
12、10=19110 所以: 112+123+134+1910 =(112)+(1213)+(1314)+(19110) =112+1213+1314+19110 =1110=910 问题:计算:(1)112+123+134+120152016+120162017 (2)113+135+157 (3)113+135+157+120152017 72. 计算 (1)(3)(75)(13)47 ; (2)56(122250.6) ; (3)(12+131415)(20) 73.解方程:x x24=5x761 74.计算:1+2+3+2007+(1)+(2)+(3)+(2008) 75.计算 (1)已知
13、|a|=3,|b|=2,且|a+b|=(a+b),则a+b的值 (2)计算24+68+1012+2016+2018 76.计算: |3|2(1) 77.计算与化简 (1)23 89 ( 23 )2 (2)x+(2x2)(3x+5) 78.若|a|=5,|b|=3,求a+b的值;若a+b0,求ab的值79.20(7)|2|80.计算 (1)(3.6)(2.5) (2)(49)(91)(+51)+(9) ; (3)312(13)+223+(12) (4)1+(2)+|23|5 . 81.(1)5x-(3x-2y)-3(x+y),其中x=-2,y=1(2)先化简,再求值:a(a1)(a2b)= 5求
14、:代数式 a2+b22ab的值82.解方程:12x71=x+33 83.解方程: (1)4x3(19x)=6x7(9x) (2)2 12 (x1)= 15 (x+2) (3)2x+13 x16 =2 (4)3y14 1= 5y76 (5)x+42 x+5= x+33 x26 84.解方程: 2x14+1=x+36 85. (1)(7)(10)+(8)|-2| (2)24(142356)112 (3)5x27x+32x2+5x2 (4)8a2b+2(2a2b3ab2)3(4a2bab2) 86.解方程: (1)3x+7=32-2x (2)12y3=3y+173 87.解下列方程: x221=x+
15、13x+86 . 88. (1)6abab8ab (2)(5a3b)2(a2b) 89.解方程 (1)5x+5=93x . (2)143x4=5x+36 . (3)x30.5x+40.2=1.6 . 90.先化简,再求值: 3(4a2+2a)(2a2+3a5) ,其中 a=2 . 91.计算下列各式: (1)(3 57 )+(+15.5)+(16 27 )+(5 12 ); (2)13 56 ( 34 )+ 56(712) ; (3)(17 34 )(+6.25)(8 12 )(+0.75)22 14 ; (4)0.125+(8 14 )( 78 )2; (5)(2 25 )(4.7)+(0.
16、5)+|2.4|(+3.2) 92.当a =12 , b=3 时,求多项式3(a22ab)3a22b+2(ab+b)的值 93.计算:(1)2223(23)(3)2(2)1651+38273352994.计算:12+3(2)3(6)( 13 )2 95. (1)6.8(4.2)(1)3 (2)( 12 56 712 ) (24 ) 96.计算: 16(11)+(8) 97.计算: (1)|2|+(2)2+(7)0(13)1 ; (2)a3a5+(3a4)2a2 98.解下列方程: (1)3x-(x-1)=5 (2)x3x212=223x . 99.关于x的方程(a2-1)x2+(a-1)x+4
17、a-2=0是一元一次方程,求a的值 100.计算题 (1)计算:(4)2( 34 )+( 58 ) (2)计算:(2)3(10.5) 13 2(4)2 答案解析部分1.答案解:原式 4+13=33=6. 2.答案解: 3x2y25xy2(4xy23)+2x2y2=3x2y25xy24xy2+3+2x2y2=3x2y2xy2+3+2x2y2=3x2y2xy232x2y2=x2y2xy23 3.答案解:原式= 81(27)83+(8) = 3(163) = 3+163 = 253 4.答案:(1)解:去括号得:5x+63x=8,移项合并得:2x=2,解得:x=1(2)解:去分母得:5x158x2=
18、10,移项合并得:3x=27,解得:x=95.答案:(1)解:原式=20+2=18;(2)解:原式=187.5+3112.5=38+31=7;(3)解:原式= 18 + 58 1 13 4 23 = 12 6=5 12 ;(4)解:原式=1+1+ 37 +5+ 47 +4=12 6.答案:(1)解:原式=42+ 16 16 (2)2;=16+14=16+4=12(2)解:原式=(4x3y)3y+2xy5x=4x3y+3y2x+y5x=3x+y7.答案解:解方程3(x1)2(x+1)=3 ,得x=2,因为解相同,将x=3 代入 2x13x+a2=1 ,解得: a=28.答案:(1)解: 10x1
19、2x=57 , 2x=12 ,x=6 (2)解: 3(3x1)12=2(5x7) , 9x312=10x14 ,9x10x=14+3+12 ,x=1 ,x=1 9.答案:(1)解:移项得:3x+2x=32-7,合并同类项得:5x=25,系数化为1得:x=5.(2)解:移项得:x-32x=1+3,合并同类项得:-12x=4,系数化为1得:x=-8. 10.答案解:移项得:4x-2x=12+4,合并同类项得:2x=16,系数化为1得:x=811.答案:(1)解:-1(2)解:1 12.答案:(1)解: 3x3+62x+6+7, 3x2x6+7+36,x10;(2)解:6+3x2(82x), 6+3
20、x184x,3x+4x186,7x12,x 127 13.答案:(1)解:去括号, 得6x+9=11x-6,移项,得9+6=11x-6x,合并同类项,得15=5x,系数化为1,x=3(2)解:去括号,3x-6x+6=3-2x-6,移项,3x-6x+2x=3-6-6,合并同类项,-x=-9,系数化为1,x=9 14.答案解:原式=x2y+xy23xy2+x2y=2xy2 , 当x= 12 ,y=1时,原式=2 12 1=115.答案:(1)A+B=8xyx2+y2+x2y2+8xy=16xy(2)2A3B=2(8xyx2+y2)3x2y2+8xy=16xy2x2+2y23x2+3y224xy=8
21、xy5x2+5y2 16.答案解:去括号得:4x60+3x4, 移项得:4x+3x4+60,合并得:7x56,解得:x817.答案:(1)解:原式= x32y33x2yx3+3y3+4x2y=y3+x2y ;(2)解:原式= 10x35y12x+30y=2x5y 18.答案解:(1 12 )+(2000 56 )+4000 34 +(1999 23 ) =1+( 12 )+(2000)+( 56 )+4000+ 34 +(1999)+( 23 ),=1+(2000)+4000+(1999)+( 12 )+( 56 )+ 34 +( 23 ),=(2)+ 34 ,= 54 19.答案解:原式 1
22、4+34-(2+3-2+3) 12 320.答案:(1)解: 10(5)+(9)+6 =10+5-9+6=12;(2)解: 14+(2)(16)|3| =-1+26-3=-1+12-3=8.21.答案:(1)(+6)+(9) =6-9=3 (2)(13)25 =(13+25) =(515+615) =1115 (3)|314+413|516 =|134+133|316=|13312+13412|316 =1312316 =13126212=4912 22.答案解:去分母,得4(2x-3)-5(x-2)=-20, 去括号,得8x-12-5x+10=-20, 移项,得8x-5x=-20+12-10
23、, 合并同类项,得3x=-18, 系数化为1,得x=-6. 23.答案:(1)解:移项得:0.5 x +1.3 x6.5+0.7,合并同类项得:1.8x=7.2,解得:x=4(2)解:去分母得:5(2x-1)=2(6x-7)-10,去括号得:10x-5=12x-14-10,移项得:10x-12x=-14-10+5,合并同类项得:-2x=-19,解得:x= 192 . 24.答案:(1)解: 13(x2)=x5 , 去括号,得: 13x+6=x5 ,移项合并,得: 4x=12 ,把 x 系数化为1,得: x=3 ;(2)解: 2x133x6=1 , 去分母,得: 2(2x1)(3x)=6 ,去括
24、号,得: 4x2+x3=6移项合并,得: 5x=1把 x 系数化为1,得: x=15 .25.答案:(1)解:原式= 47(512)37512+512 = 512(4737+1) =0(2)解:原式= 16+812+1 =-16+4+1= -11 26.答案解:23(x+1)=0的解为x= 13 ,则 k+x23k2=2x 的解为x=3,代入得 k32 3k2=6,解得:k=1故答案为:127.答案解:由题意得:|m|=1且1m0,解得m=1当m=1时,方程为2x+2=0,解得x=-1.28.答案:(1)解:原式= 36(2312)8 =24-18-8= -2(2)解:原式=4+4-2 =62
25、9.答案:(1)解:去括号得:4x+3=2x-2+1,移项合并得:2x=-4,解得:x=-2(2)解:移项得:0.5x+1.3x=6.5+0.7,合并同类项得:1.8x=7.2,解得:x=430.答案:(1)解: 255445(32) =254545(132)=12 ;(2)解: 14(10.5)23+(3)2 =11223+9=113+9=233.31.答案解:(1)移项合并得:1.8x=5.4,解得:x=3;(2)去分母得:15+5y5=6y+3,移项合并得:y=732.答案解:原式=13+730+5=2030+5=10+5=533.答案:(1)解:4639+5741=10380=1042
26、0(2)解:90772932=895960772932=123028(3)解:31175=15585=15625(4)解:176523=5857 34.答案:(1)解:原式= 1383213+2364+12 =4+4-4+12 =92或412 (2)解:原式= -818+2312-1212-1412+1 =-1+8-6-3+1 =-1 35.答案解:(1)去分母得:2x3x+2=204x,移项合并得:3x=18,解得:x=6;(2)去分母得:122t+2=t+1,移项合并得:3t=13,解得:t=133 36.答案:(1)解:原式=12+18715=3022=8(2)解:原式=4+39 13
27、=4+33=4 37.答案:(1)解:原式2317716=(23+7)-(17+16),30333.(2)解:原式 (321+13) 15 56 15 1930 .(3)解:原式(26.54)18.54(6.4)6.4=26.5418.546.46.4=-(26.54+18.54)+(6.4-6.4)45.08+0=45.08.(4)解:原式4 78 3 18 5 12 4 14=(-478-318)+(512-414)81 14 6 34(5)解:原式2.44.70.52.43.2=(2.42.4)+4.7(0.53.2)=0+4.73.71. 38.答案:(1)解: 12-(-8)+(-7
28、)-15=12+8-7-15=-2(2)解: 122345+3122=1+845+314=1+854+33=1+10+9=18 .39.答案:(1)解:179721854=1785960721854=106416(2)解:3607=51+1807=5125+300751254340.答案解:由 0.5mxn3 与 5m4ny 是同类项,可得 x=4,y=3(5x2y4y32xy2+3x3)(2x35xy23y32x2y)=(2x2y5x2y)+(3y34y3)+(5xy22xy2)+(3x32x3)=3x2yy3+3xy2+x3=3xy(yx)+(x3y3)=(xy)3把 x=4,y=3 代入
29、,得 =(xy)3=(43)3=141.答案:(1)解:原式=-11-9+3=-17(2)解:原式= 1+121413+16 = 1+1234+212 = 1+12112 =-1+1=042.答案:(1)解:原式=362616+414 =166+414 =-1+(-56) =-(1+56) =-57(2)解:原式=11112136 =111166 =11566 =1166 =-1-1 =-(1+1) =-2 43.答案:(1)解:去括号得: 5-5x=-4x+2, 移项合并得:x=3;(2)解:去分母得:3x-2(5+x)=6, 去括号得:3x-10-2x=6移项合并得:x=16,44.答案:
30、(1)(-93)(-2)2 =-124=-3(2)35(-21)(- 23 ) =- 53 + 23 =-145.答案:(1)解:原式=12514+39=8(2)解:原式=(122613)=(27)=27(3)解:原式=16+ 278 29 6 94 =16+ 34 272 =16 512 = 832(4)解:原式= 12 (9 19 +0.7)( 67 )= 12 310 67 = 970 46.答案解: 4+(6)(4)+20=46+4+20=22. 47.答案:(1)解:原式=11610(2)解:原式=414(3)解:原式=10625(4)解:原式=3549 48.答案解:原式 =279
31、128=34=1. 49.答案解: 2(a2b2)+3ab2a2+2b22ab=2a22b2+3ab2a2+2b22ab=(2a22a2)+(2b22b2)+(3ab2ab)=ab 50.答案:(1)解:原式=-12+2 =-10;(2)解:原式=-42-3(-1) =-8+3 =-5 51.答案:(1)解:6x+4 -4x= -2,2x= -6,x= -3(2)解:去分母得:3(2x1)=124(x+2),去括号得:6x3=124x-8,移项合并得:10x=7,解得:x= 71052.答案:(1)原式=5-(-3)=5+3=8 (2)原式=41234=412434=2-3=-1 53.答案解
32、:原式=16 649 14 14=16 964 12= 94 12= 74 .54.答案:(1)解:去括号得:3x-3-x=1-2x+1移项得:3x-x+2x=1+1+3合并同类项得:4x=5化系数为1:x= 54(2)解:去分母得: 2(x1)(x+2)=3(4x)+6 去括号得:2x-2-x-2=12-3x+6移项得:2x-x+3x=12+6+2+2合并同类项得:4x=22化系数为1得:x= 11255.答案解:(1) |ab+2|+|a+1|=0 , ab+2=0 , a+1=0 ,解得: a=1 , b=2 ; ( 2 )当 a=1 , b=2 时,1(a1)(b+1)+1(a2)(b
33、+2)+1(a2016)(b+2016)=123+134+120172018 =12+1313+14+12019+12020 =12+12020 =10092020 56.答案:(1)解: (1)2+(12)15(2019)0=1+25=2(2)解: (yx)2n(yx)3=(yx)2n+3(3)解: (5x3y23x2y3)(xy)3x(2xyy2) =5x2y+3xy26x2y+3xy2 =11x2y+6xy2 57.答案:【解答】解:原式=5x+5,当x=2时,原式=52+5=1558.答案解:a+12与-8+b互为相反数 (a+12)+(-8+b)=0即a+12-8+b=0,即a+b=
34、-4故答案为:-459.答案:(1)解: 4x-1=3x+2,移项,得4x-3x=2+1,合并同类项,得x=3. (2)解: 5x12 =1- x+14 ,两边同乘4,得2(5x-1)=4-(x+1),去括号,得10x-2=4-x-1,移项,得10x+x=4-1+2.合并同类项,得11x=5,两边同除以11,得x511. 60.答案解:(1)5.6+4.4+(8.1)=108.1=1.9;(2)(7)+(4)+(+9)+(5)=74+95=16+9=761.答案:解:原式=9+568=1414=0 62.答案:(1)解:原式=ab2(8a9b3) =8a10b5;(2)解:原式=3a2b3a2
35、+3a2b2ab3a2b4b2 , =9a4b+6a3b212a2b3;(3)解:原式=6x4(2x2)4x3(2x2)+2x2(2x2) =3x2+2x1;(4)解:原式=(2x2+5x10x25)(2x26x)=x2563.答案解:|a1|=4,|2b|=5,a1=4,2b=5,a=5或3,b=7或3,当a=5,b=7时,ab=57=2,a=3,b=7时,ab=37=10,a=5,b=3时,ab=5(3)=8,a=3,b=3时,ab=3(3)=0,所以,ab的值是2或10或8或064.答案:(1)解: 原式=3+2-4,=1. (2)解: 原式=1223-1212-(-8),=8-6+8,
36、=10. 65.答案:(1)解:(1)-1-(-2)+(-3)+(-4)-(-5)=-1+(+2)+(-3)+(-4)+(+5)=-1+(-3)+(-4)+(+2)+(+5)=-8+(+7)=-1(2)解: 18+1558+25=(1858)+(15+25)=34+35=320(3)解:(479)(316)(+229)+(616)=(479)+(+316)+(229)+(616)=479+316229616=(479229)+(316616)=73=1066.答案解:2.7-(-3.3)=2.7+3.3=667.答案:(1)解:去括号得:3x-7x+7=5-2x-6, 移项合并得:-2x=-8
37、,解得:x=4;(2)解:去分母得:10x-5x+5=20- 2x-36, 移项合并得:7x=-21,解得:x=-368.答案:(1)解:3x+9x=-1212x=-12x =-1(2)解:6y-10=-3+3y+16y-3y=-3+1+103y=8y=83(3)解:3(x-2)=2(4-2x)3x-6=8-4x3x+4x=8+67x=14x=2(4)解:2(5x+4)-12x=3(3x-2)10x+8-12x=9x-610x-9x -12x=-8-6-11x=-14x=1411 69.答案:(1)解:3x-(x-5)=2(2x-1), 3x-x+5=4x-2,2x-4x=-2-5,-2x=-
38、7,x= 72 ;(2)解: y+282y16=1 , 3(y+2)-4(2y-1)=24,3y+6-8y+4=24,-5y=14,y= 145 ;(3)解: 2x3y=53x+2y=12 , 2得:4x-6y=-10,3得:9x+6y=36,+得:13x=26,解得x=2,将x=2代入得:4-3y=-5,y=3,原方程组的解是 x=2y=3 ;(4)解: x+13=y12+1623x+y2=53 , 将方程组化简得 2x3y=44x+3y=10 ,+得:6x=6,解得x=1,将x=1代入得:4+3y=10,y=2,原方程组的解是 x=1y=2 .70.答案解:|a|=2,|b|=3,a=2
39、b=3,a+b0,a=2,b=3,或a=+2,b=3,a+b=1或571.答案:(1)解:原式 =(112)+(1213)+(1314)+(1201512016)+(1201612017) =1213+1314+1201512016+1201612017 =1 12017 = 20162017 (2)解:原式= 12(113)+12(1315)+12(1517) =12(113+1315+1517) =12(117) = 37 (3)解:原式 =12(113)+12(1315)+12(1517)+12(1201512017) =12(113+1315+1517+1201512017) =12(
40、112017) = 10082017 72.答案:(1)解:原式= (3)(13)(75)47=1(45)=45(2)解:原式= 5612+(56)(225)+(56)(0.6)=10+2+12=152(3)解:原式= 12(20)+13(20)14(20)15(20)=10203+5+4=373 73.答案解:去分母,得:12x3(x2)2(5x7)12 去括号,得:12x3x+610x1412移项,得:12x3x10x14126合并同类项,得:x32系数化为1,得:x32.74.答案解:原式=(11)+(22)+(33)+(20072007)+(2008) =200875.答案:(1)解:
41、|a|=3,|b|=2,且|a+b|=(a+b),即a+b0,a=3,b=2或2,当a=3,b=2时,a+b=32=5;当a=3,b=2时,a+b=3+2=1故a+b的值为5或1;(2)解:24+68+1012+2016+2018=(24)+(68)+(1012)+(20142016)+2018=222+2+2018=2(201622)+2018=2504+2018=1008+2018=101076.答案解:原式 =32(1) 77.答案:(1)解:原式=8 98 49 =4(2)解:原式=x+2x23x5=2x7 78.答案解:|a|=5,|b|=3,a=5,b=3,a+b=8或2或2或8;
42、a=5,b=3,且a+b0,a=5,b=3,ab=8或279.答案解:20(7)|2|=20+72=272=2580.答案:(1)解:原式=-3.6+2.5=-1.1(2)解:原式=-49+91-51-9=-18(3)解:原式=3 12 + 13 +2 23 - 12 =3+3=6(4)解:原式=1-2+5-5=-1 81.答案:(1)原式=5x-3x+2y-3x-3y=-x-y,当x=-2,y=1时,原式=-(-2)-(-1)=3(2)原等式变形得:a2-a-a2+b=-5a-b=5a2+b22-ab=a2+b22-2ab2=a2+b22ab2=ab22将a-b=5代入上式得:原式=522=
43、252 82.答案解:去分母,得3(12x)21=7(x+3),去括号,得36x21=7x+21,移项,得6x7x=213+21,合并,得13x=39,系数化1,得x=3,则原方程的解是x=383.答案:(1)解:去括号得:4x57+3x=6x63+7x, 移项合并得:6x=6,解得:x=1;(2)解:去分母得:205x+5=2x+4, 移项合并得:7x=21,解得:x=3;(3)解:去分母得:2(2x+1)(x1)=12, 去括号得:4x+2x+1=12,移项合并得:3x=9,解得:x=3;(4)解:去分母得:3(3y1)12=2(5y7), 去括号得:9y312=10y14,移项合并得:y
44、=1;(5)解:去分母得:3x+126x+30=2x+6x+2, 移项合并得:4x=34,解得:x=8.584.答案解: 2x14+1=x+36 去分母,得, 3(2x1)+12=2(x+3) , 去括号,得, 6x3+12=2x+6 ,移项,得, 6x2x=6+312 ,合并同类项,得, 4x=3 ,系数化为1,得, x=34 .85.答案:(1)解: (7)(10)+(8)|-2| =-7+10+(-8)+(-2)=-7;(2)解: 24(142356)112 = 16(142356)12 = 16(141223125612) = 16(3810) =-16-(-15)=-16+15=-1
45、;(3)解: 5x27x+32x2+5x2 = (5x22x2)(7x5x)+(32) = 3x22x+1 ;(4)解: 8a2b+2(2a2b3ab2)3(4a2bab2) = 8a2b+4a2b6ab212a2b+3ab2 = (8a2b+4a2b12a2b)(6ab23ab2) = 3ab2 86.答案:(1)解:移项得:3x+2x=32-7合并同类项得:5x=25系数化为1得:x=5(2)解:去分母得:7(1-2y)=3(3y+1)-63去括号得:7-14y=9y+3-63移项得:-14y-9y=3-63-7合并同类项得:-23y=-67系数化为1得:y= 6723 87.答案解:去分
46、母,得 3(x2)6=2(x+1)(x+8), 去括号,得3x66=2x+2x8, 移项,得3x2x+x=28+6+6,合并同类项,得2x=6,系数化为1,得x=388.答案:(1)解:原式= (-6+1+8)ab = 3ab (2)解:原式 = 5a3b-2a+4b = (5-2)a+(-3+4)b =3a+b89.答案:(1)解: 5x+5=93x 5x+3x=95 8x=4 x=12 (2)解: 143x4=5x+36 123(43x)=2(5x+3) 1212+9x=10x+6 x=6 (3)解: x30.5x+40.2=1.6 0.2(x3)0.5(x+4)=0.16 0.2x0.6
47、0.5x2=0.16 0.3x=0.16+2.6 x=9.2 90.答案解:原式 =12a2+6a2a23a+5 =10a2+3a+5 当 a=2 时,原式 =10(2)2+3(2)+5 =406+5 =39 91.答案:(1)解:原式=3 57 16 27 +15.55 12 =20+10=10(2)解:原式=13 56 + 34 + 56 + 712 =16(3)解:原式=17 34 6.25+8 12 0.7522 14 =1720=3(4)解:原式=0.125+ 78 8 14 2=9 14(5)解:原式=2 25 +4.70.5+2.43.2=1 92.答案解:原式=3a26ab3a
48、2+2b2ab2b=( 3a2 3a2 )+( 6ab 2ab )+( 2b 2b )= 8ab当a =12 , b=3 时,原式8ab=-8 (12)(3) = -1293.答案解:(1)原式=432(23)9=6+6=0;(2)原式=1651+115213529=131723529=964394.答案解:原式=124+54=29 95.答案:(1)解:原式=6.8(4.2)+ (1)3 =6.8+4.21=10(2)解:原式= 12 (24)+ 56 (24) 712 (24)=1220+14=18. 96.答案解:原式 =1(6+118) =19 =10 97.答案:(1)解:原式2+4+1+3 10(2)解:原式(a8+9a8)a210a8a2 10a698.答案:(1)解:3xx+1=5,3xx=51,2x=4,x=2;(2)解:4x(x2)=248x,4xx+2=248x,4xx+8x=242,11x=22,x=2. 99.答案解:(a2-1)x2+(a-1)x+4a-2=0是关于x的一元一次方程,a21=0a10 , 解得:a=-1. 100.答案:(1)解:原式=16( 34 58 )=1210=22(2)解:原式=8 12 13 (14)=8+ 73 =5 23