1、人教版数学七年级上册期末计算题100例附解析(9)1.解方程: (1)3+12x=7x+32 (2)122(2x+1)=3(1+x) (3)3x+52=2x13 (4)5x76+1=3x14 (5)x+2(x3)3=6x76 2.计算: (1)42|3|(5); (2)32+5( )(4)2(8) 3.一个多项式与2x35x6的差是x32x2x4,求这个多项式 4.计算: (3m2)(3m+2)(2m1)(m+4)7m 5.解方程: (1)x2x26=x13 (2)x0.30.050.1x0.02=1 6.化简求值:(2x2y4xy2)(3xy2+x2y),其中x=1,y=2 7. 计算: (
2、1)(5)(10)(32)(7); (2)8.4104.25.7. 8.用简便方法计算(1)392324(12)(2)(23124115)(60)9.计算: (1)253448152637 (2)1051848+35.285 10.计算:(1)4|3|2(3)2 11.解方程: (1)62(x1)=x ; (2)3x13=14x16 . 12.解下列方程(组): (1)2x+13=1x15 (2)2x+y=x+3xy=1 13.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)
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:(2000 56 )+(1999 23 )+4000 34 +(1 12 )14.已知|a|=3,b2=4且ab,求a+b的值 15.已知: A=(2x+1)(x2),A2B=x6 ,求B+A 16.计算: (1)(9a2x4)(13a2c) ; (2)(2t+1)2(2t+1)(2t1) ; (3)先化简,再求值: (3x+2)(3x2)5x(x1)(2x1)2 ,其中 x=13 17.用等式的性质解方程
4、3x+1=7 18.已知 |x|=3,|y|=7. (1)若xy,求x+y的值; (2)若xy0,求x-y的值 19.计算: (1)(2)2(3)(4) (2)(122356)(60) 20.解方程: (1)3x4(x+1)=1 (2)x32 2x+13 =1 21.计算 (1)5+(13)+(14) (2)1226(27) (3)177+(33)49 (4)314+(235)+534+(725) 22.解方程: (1)3x+1=2 (2)x13=x21 23.计算: (1)23+13(2005+3)0(13)2 (2)(2x2y)23xy(6x2y) (3)(2x+3y)(3y2x)+(x3
5、y)(x+3y) (4)(2x+y+1)(12xy) 24.化简求值;5a23a2(2a1)+4a2,其中a= 12 25.计算 (1)26+(-18)+5+(-16) (2)9(11)3(3) (3)(24)(12+56712) (4)3+5022(15)1 26.已知多项式(4m)xy5x+y1不含二次项,求m的值 27.解方程: 12x33x=x123 . 28.计算: (1)(3458+912)(124) (2)(-208)( 12 )-192( 12 )+(-2)2x( 12 ) 29.先化简,再求值:-2a2+(-4a+5a2)-(3a2+2a-1),其中a= 12 30.解方程:
6、 (1)9+7x=5-3x; (2)5x-11=3x-9 31.计算下列各题: (1)16(5)+23| 12 | (2)22( 32 )2 29 +6| 43 2|+(1)5( 52 )2 32. 计算: (1)( 12 )052 (2)201199+1(简便运算) (3)(y)8(y2) (4)4a(ab+1) (5)(9a2b4)( 13 a2c) (6)(a2)2+2(a1)(a+2) 33.计算: (1)(12)+(+8)+(9); (2)36+(24)+(+64)+(76); (3)(41)+45+(9)+(+20); (4)(78)+(+5)+(+78); (5)(13)+(16
7、)+(14)(6); (6)(+19)+(27)(+10)(23)+(49) 34.解方程: (1)3(2x1)=15 (2)x+12+x23=4 35.看数轴,化简:|a|b|+|a2|36.已知M=x2ax1,N=2x2ax2x1 (1)求N(N2M)的值; (2)若多项式2MN的值与字母x取值无关,求a的值 37.8+ (3)2 (2) 38.计算:有理数的运算 (1)2(4)+8(2)+3 (2)36(23+34112) (3)23814(2)2 . 39.解方程:2x(x1)x(2x+3)=15 40.先化简,再求值:(1)2x3+4x-13x2-(x-3x2+2x3),其中x=3(
8、2)(6a2+4ab)-2(3a2+ab-12b2),其中a=2,b=141.计算:6(15)2|1.5|42.计算: (1)5(1 23 ); (2)( 34 )( 37 )(1 16 ) 43.先化简再求值: (b+3a)2(25b)(12ba) ,其中 a=2,b=1 44.计算 (1)20+(14)(18)13 (2)(2 15 )+(1 13 )(2 16 )(4 15 ) (3)( 12 59 + 712 ) (136) (4)(37) 0.125 (213) (8) (5)99717236 (6)(123)(9)19(527) 45.已知关于x的方程 5x+m3 x12 m的解为
9、非负数,求m的取值范围 46.解方程: (1)5x21=11x3 ; (2)4(x+12)+9=53(x1) 47.计算: (1)(6)(+15)+4(15) (2)23(4)2+3 (3)(381634)(24) (4)14(104)13(2)26 48.计算: (1)-8+(-1.2)-(-0.6)+(-2.4) (2)-2+(-4)2-(-3)-52-|-2|, 49.计算: (1)( 16 + 34 512 )(12) (2)|5|(12)4( 12 )2 50.计算 (1)|2|+14+(1)2018 (2)2224(11256+38) 51. (1)计算: 12+3(2)3(6)(
10、13)2 ; (2)先化简,再求值: 12x2(x13y2)+(32x+13y2) ,其中 x=2 , y=23 (3)解方程: 2x163x18=1 52.解方程: (1)2(x+8)=3x1 (2)2x13=1x+12 53. 计算 (1)(2.8)+7.2+5.5+(4.2) (2)(7)(10)+(8)(2) (3)23(94)+(34)89 (4)722 1449(225) (5)14(4956+34)(36) (6)(4)3+232+(6)(12)2 54.解下列方程: (1)3(4x3)=7 (2)x532x2=x 55.计算或化简下列各小题: (1)(ab3)2+(a)2(b2
11、)3 ; (2)(2)2(3)0+(13)1 (3)(3x+y)2(3xy)2 ; (4)(a+3b+c)(a+3bc) . 56.计算: (1)12+5+(16)(18) (2)(3)56(14) (3)24(12+3413) (4)(2)2|6|+4(1)2018 57.计算: (1)4839+6731 (2)18021175 58.解方程:3y+14=22y13 59.解方程:(1)2(52x)=3(x43)(2)x+135x16=160.计算:(1)(34+15678)(24)(2)23+|58|+24(3)61.根据所给的条件,求出各式的值: (1)若 |a3| 与 (b2)2 互为
12、相反数,求 (a)b 的值. (2)已知 |a|=3 , |b|=2 ,且ab 0,求a-b的值. 62.计算: (1)-49+91-5+(-9) (2)0.5+(14)2.75+(12) (3)23 +( 15 )1+ 13 (4)2317(7)+(16) 63.先化简,再求值:5(3a2bab2)4(ab2+3a2b);其中a=1,b=12 64.计算: (1)18 16 11 (2)6 16 24 65.计算 (1)15(8)+(11)12 (2)(2312)30(15) 66.把下列各式写成省略括号的和的形式: (1)(7)(8)(1)(5)(3)_; (2)9(5)(6)(7)_;
13、(3)(3)(4)(19)(11)_; (4)0.21(5.34)(0.15)(10 15 )_. 67.有理数a,b,c在数轴上的位置如图所示,试化简: |2ab| |bc| |ca| .68.计算:1-2+3-4+5-6+99-100; 69.计算: (1)23-17-(-7)+(-13) (2)24(56+18+34) (3)(5)(4)+3(2) (4)(1)4+(112)3(4+23) 70.解下列方程 (1)3x-7(x-1)=3-2(x+3) (2)2x-(x+10)=6x (3)x+232x12=1 (4)0.4x+0.90.50.03+0.02x0.03=1 71.化简:2(
14、a4)3+(2a3)2(a2)3+a2a10 72.计算:14(10.5)132(3)273.(12)2(2)3(3)335 74.4x16 =1 3x12 75.化简并求值:已知a+b=12,ab=6,求代数式(4a3b2ab)(a6bab)的值76.化简求值:3x25x(x22x)其中x1 77.化简:x22xy2x2+3xy 78.解方程 (1)13 x=8- 12 (20-x) (2)2y13=y+241 79.计算或化简: (1)2 0 +(2) 2( 13 )1 (2)a5 (a4)2 (a2)3 (3)(a+1) 2 a ( a3) 80.有理数计算 (1)(2.4)+(3.7)
15、+4.6+5.7 (2)314+235534(225) (3)032(2)3(4) (4)35(1312)54 81.先化简,再求值: (x3)2+2(x2)(x+7)(x+2)(x2) ,其中 x2+2x4=0 . 82.计算题:有理数的运算 (1)(45)(9)(3) ; (2)2314+|4|3(2)4 83.4、5、7这三个数的和比这三个数绝对值的和小多少? 84.计算: (1)150+5(63) (2)6(16)(16)8 85.解一元一次方程 (1)53(y 13 )=3 (2)2y13 = y+24 1 (3)4x1.50.5 5x0.80.2 = 1.2x0.1 86.已知方程
16、 2x35 23 x3与方程3n 14 3(xn)2n的解相同,求(2n27)2的值 87.(1)3142(3)2 88.已知 |a|=1,|b|=2,|c|=3, 且abc,求abc的值。 89.把下列各式分解因式(1)-x3y+2x2y-2xy(2)a2(x-1)+b2(1-x)(3)x2+4x-5(4)a2-b2+2a+190.计算: (1)(37)+(47); (2)(53)+16; (3)(210)87; (4)1.3(2.7); (5)(7)+11+3+(2) (6)(83)+(+26)+(41)+(+15) 91.计算 (1)5(8)16 (2)(1256712)(36) (3)
17、32+|22|+3631 92.观察 112 + 123 =(1 12 )+( 12 13 )=1 13 = 23 (1)计算: 112 + 123 + 134 + 120132014 = (2)计算: 113+135+157+199101 93.解方程: 5x+13 2x16 =1 94.计算:-36x(23+34-112)95.解方程: (1)3(2x1)=52(x+2) (2)x52=1+2x+33 96.计算: (1)(11252416)24 (2)32229(32)248(2)(12) 97.已知 (2m6)2 与n+2互为相反数,则求方程mx +3n=6的解 98.化简求值:2x2
18、-54x2-(3x2-x-1)-3,其中x=32 99.解方程:4x6=2(3x1) 100.计算: (1)108(2)3(4)2(2); (2)( 34 )(221 13 23 );。 (3)(2)3(3)222 14 8 12 ( 12 )2. 答案解析部分1.答案:(1)解: 3+12x=7x+32 12x7x=32+3 5x=35 x=7 (2)解: 122(2x+1)=3(1+x) 124x2=3+3x 4x3x=3+212 7x=7 x=1 (3)解: 3x+52=2x13 3(3x+5)=2(2x1) 9x+15=4x2 5x=17 x=175 (4)解: 5x76+1=3x14
19、 2(5x7)+12=3(3x1) 10x14+12=9x3 x=1 (5)解: x+2(x3)3=6x76 6x+4(x3)=36(x7) 6x+4x12=36x+7 11x=55 x=5 2.答案:(1)解: 原式=-4+23+5,=-4+6+5,=7.(2)解: 原式=-9-8-16(-8),=-9-8+2,=-(9+8-2),=-15. 3.答案解:依题可得:(x32x2x4)(2x35x6),x32x2x42x35x6,3x32x24x2.4.答案:解 (3m2)(3m+2)(2m1)(m+4)7m = 9m24(2m2+7m4)7m = 7m(m1)7m = m1 ,故答案为: m
20、1 5.答案:(1)解: x2x26=x13 去分母得, 3x(x2)=6x2去括号得, 3xx+2=6x2移项合并得,-4x=-4系数化为1,得:x=1;(2)解: x0.30.050.1x0.02=1 方程可化为 10x3510x2=1去分母,得: 20x3(510x)=6去括号,得: 20x15+30x=6移项合并得:50x=21系数化为1,得, x=2150 .6.答案解:(2x2y4xy2)(3xy2+x2y) =2x2y4xy2+3xy2x2y=x2yxy2 , 当x=1,y=2时,原式=(1)22(1)22=12+14=2+4=67.答案:(1)解:原式510327,(532)(
21、107),3717,20.(2)解:原式(8.44.2)(105.7),12.615.7,3.1.8.答案解:(1)原式=(40+124)(12)=40(12)12412=48012=47912;(2)原式=23(60)+11260+11560=40+5+4=319.答案:(1)解:253448152637=10811(2)解:1051848+35.285=1051848+35176=1403554.10.答案解:(1)4|3|2(3)2 13(29)13(7)1+212211.答案:(1)解:去括号,得62x+2=-x, 移项合并,得-x=-8,解得x=8(2)解:去分母,得2(3x-1)=
22、6-(4x-1), 去括号,得6x2=64x+1,移项合并,得10x=9,解得x=0.912.答案:(1)解: 2x+13=1x15 去分母,可得:5(2x+1)=15-3(x-1),去括号,可得:10x+5=18-3x移项,合并同类项,可得:13x=13,解得x=1,经检验,x=1是原方程的解(2)解: 2x+y=x+3xy=1 +,可得:3x=x+2,解得x=1,把x=1代入,可得:1-y=-1,解得y=2,方程组的解是 x=1y=2 13.答案解:原式=(2000)+( 56 )+(1999)+( 23 )+4000+ 34 +(1)+( 12 )=(20001999+40001)+(
23、56 23 + 34 12 )=01 14=1 1414.答案解:由|a|=3,b2=4,得a=3,b=2由ab,得a=3,b=2,当a=3,b=2时,a+b=3+2=5;当a=3,b=2时,a+b=3+(2)=1,综上所述:a+b=5或a+b=115.答案解:把 A=(2x+1)(x2) 整体代入到 A2B=x6 式子中可得: (2x+1)(x2)2B=x6 ,2x24x+x22B=x6 ,2x24x+x2x+6=2B ,2x24x+4=2B ,B=x22x+2 ,B+A=x22x+2+(2x+1)(x2) ,= x22x+2+2x23x2 ,= 3x25x 16.答案:(1)解: (9a2
24、x4)(13a2c) = (139)(a2a2)x4c = 3a4x4c ;(2)解: (2t+1)2(2t+1)(2t1) = 4t2+4t+14t2+1 = 4t+2 (3)解:原式 =9x24(5x25x)(4x24x+1) =9x245x2+5x4x2+4x1=9x5 .当 x=13 时,原式 =9(13)5=8 17.答案解:方程两边都减去1,得 3x+11=71,化简,得3x=6两边除以3,得x=218.答案:(1)解:|x|=3,|y|=7, x=3 , y=7 ,xy,x=3,y=7或x=-3,y=7;当x=3,y=7时,x+y=3+7=10;当x=-3,y=7时,x+y=-3
25、+7=4;综上所述,x+y的值为4或10(2)解:|x|=3,|y|=7, x=3 , y=7 ,xy0,x=3,y=-7或x=-3,y=7;当x=3,y=-7时,x-y=3-(-7)=3+7=10;当x=-3,y=7时,x-y=-3-7=-10;综上所述,x-y的值为-10或1019.答案:(1)解:解:原式4128(2)解:原式30405060 20.答案:(1)解:去括号得:3x4x4=1, 移项合并得:x=5,解得:x=5;(2)解:去分母得:3x94x2=6, 移项合并得:x=17,解得:x=1721.答案:(1)解:原式 =5+(27)=22(2)解:原式 =38+27=11(3)
26、解:原式 =10+(33)+(49) =10+(82) =72 (4)解:原式 =(314+534)+(235725) =9+(10) =1 22.答案:(1)3x+1=2 , 3x=2-1 ,3x=1 ,x= 13 ;(2)x13=x21 2(x-1)=3x-6,2x-2=3x-6,2x-3x=-6+2,-x=-4, x=4.23.答案:(1)解:(1) 23+13(2005+3)0(13)2 =-8+131-1(-13)2 =-8+13-9=-1623 (2)(2x2y)23xy(6x2y) =4x4y23xy(6x2y)=2x3y2 (3)(2x+3y)(3y2x)+(x3y)(x+3y
27、) =(3y)2(2x)2+x2(3y)2=9y24x2+x29y2=3x2 (4)(2x+y+1)(12xy) =1+(2x+y)1(2x+y)=1(2x+y)2=14x24xyy2 24.答案解:原式=5a23a+4a24a2=a2+a2,当a= 12 时,原式= 14 12 2=2 14 25.答案:(1)解:原式 =31+(34)=3 ;(2)解:原式 =99+1=100 ;(3)解:原式 =1220+14=18 ;(4)解:原式 =35014151=12 ; 26.答案解:解:关于x的多项式(4m)xy5x+y1不含二次项,4m=0,m=427.答案解: 12x33xx123 ,去分
28、母得:2(12x)18x3(x1)18,去括号得:24x18x3x318,移项并合并得:25x23,系数化为1得:x 232528.答案:(1)解:原式=18-15+18=21(2)解:原式=(-208-192+4)( 12 )=0( 12 )=0 29.答案解:原式=-2a2-4a+5a2-3a2-2a+1 =- 6a+1当a= 12 时,原式=-6( 12 )+1 =3+1 =430.答案:(1)解:移项,得:7x+3x =5-9,合并同类项,得10x=-4,解得 x=25(2)解:移项,得;5x-3x =-9+11,合并同类项,得2x=2,解得x=1 31.答案:(1)解:原式=16+5
29、+23 12 =11 12(2)解:原式=4 94 29 +6 23 254=4 12 +9 254=1 3432.答案:(1)解:原式=1 125 = 2425(2)解:原式=(200+1)(2001)+1=40000(3)解:原式=y8(y2)=y6(4)解:原式=4a24ab+4(5)解:原式=3a4b4(6)解:原式=a24a+4+2a2+2a4=3a22a 33.答案:(1)解:(12)+(+8)+(9)=(12+98)=13;(2)解:36+(24)+(+64)+(76)=(36+64)+(2476)=0;(3)解:(41)+45+(9)+(+20)=(419)+(45+20)=1
30、5;(4)解:(78)+(+5)+(+78)=(78+78)+5=5;(5)解:(13)+(16)+(14)(6)=131614+6=37;(6)解:(+19)+(27)(+10)(23)+(49)=(194910)+(27+23)=404=44 34.答案:(1)3(2x1)=15,去括号:6x-3=15,移项:6x=18,系数化为1:x=3.(2)x+12+x23=4,两边同乘6:3(x+1)+2(x-2)=24,去括号:3x+3+2x-4=24,移项:3x+2x=24-3+4,合并同类项:5x=25,系数化为1:x=5. 35.答案解:由图可知,b0a2,原式=a+b+(2a),=2+b
31、. 36.答案:(1)解:M=x2ax1,N=2x2ax2x1,N(N2M)=NN+2M=2M=2(x2ax1)=2x22ax2(2)解:M=x2ax1,N=2x2ax2x1,2MN=2(x2ax1)(2x2ax2x1)=2x22ax22x2+ax+2x+1=(2a)x1,多项式2MN的值与字母x取值无关,2a=0,得a=2,即a的值是2 37.答案解: 8+(3)2(2)=8+9(2)=8+(18)=818=10. 38.答案:(1)解:原式 =2+44+3=5(2)解:原式 =(36)23+(36)34+(36)(112)=2427+3=48(3)解:原式 =88144=11=2 39.答
32、案解:2x(x1)x(2x+3)=15 2x22x2x23x=15,整理得:5x=15,解得:x=340.答案解:(1)原式=2x3+4x13x2x+3x22x3=83x2+3x,把x=3代入上式得:原式=83(3)2+3(3)=249=15;(2)解:原式=6a2+4ab6a22ab+b2=2ab+b2 , 把a=2,b=1代入上式得:原式=221+1=541.答案解:原式=6+0.221.5=2.742.答案:(1)解:5(1 23 ) =5 35 =3(2)解:( 34 )( 37 )(1 16 ) = 347367 = 32 43.答案:原式= b=3a4=10b12b=a13b=4a
33、5 当 a=2,b=1 时,原式 =131+42-5=13+8-5=16 44.答案:(1)解:原式=-20-14+18-13=-29(2)解:原式=(4 15 2 15 )+(1 13 +2 16 ) =2+ 56 =2 56 (3)解:原式=( 12 59 + 712 ) (36) =-18+20-21=-19(4)解:原式= (37) (213) 0.125 (8) =(3773)(0.1258) =-1(5)解:原式 =(172100)36 =123600 =359912 (6)解:原式 =531919275 =19 45.答案解:解关于x的方程: 5x+m3x12=m , 去分母得:
34、 10x+2m3x+3=6m ,移项、合并同类项得: 7x=4m3 , x=4m37 又原方程的解为非负数, x=4m370 ,解得: m34 ,m的取值范围是 m34 .46.答案:(1)解: 5x21=11x3 5x-11x=-3+21-6x=18x=-3(2)解: 4(x+12)+9=53(x1) 4x+2+9=53x+3 4x+3x=5+329 7x=-3x= 37 47.答案:(1)解:-2(2)解:5(3)解:13(4)解:5 48.答案:(1)解:原式=-8-1.2+0.6-2.4=-11(2)解:原式=-2+16+3-25-2=-10 49.答案:(1)解:原式=( 16 )(
35、12)+ 34 (12)+( 512 )(12) =29+5=2(2)解:原式=5(1)44 =516=1150.答案:(1)解:原式 =2+12+1 =3.5 (2)解:原式 =42+209 =5 51.答案:(1)解:原式= 1+3(8)(6)9=29(2)解:原式= 12x2x+23y232x+13y2= 3x+y2 把 x=2 , y=23 代入原式= 3(2)+(23)2= 649 (3)解:去分母得: 4(2x1)3(3x1)=24 整理得 -x=23 x=23 .52.答案:(1)解: 2(x+8)=3x1 2x+16=3x-12x-3x=-16-1-x=-17x=17(2)解:
36、 2x13=1x+12 2(2x-1)=6-3(x+1)4x-2=6-3x-3解得,x= 57 53.答案:(1)解:原式=(2.84.2)+(7.2+5.5)=7+12.7=5.7(2)解:原式=7+108+2=1215=3(3)解:原式= 32 23 = 136(4)解:原式=72 94 49 512 =30(5)解:原式=1+16+3027=12(6)解:原式=64+1824=70 54.答案:(1)解:去括号得:3-4x+3=7, 移项合并得:-4x=1,解得:x=- 14 ;(2)解:去分母得:2x-5(3-2x)=10x, 去括号得:2x+10x-15=10x,移项合并得:2x=1
37、5,解得:x= 152 55.答案:(1)解: (ab3)2+(a)2(b2)3 = a2b6+a2b6=2a2b6(2)解:(2) (3) + (13)1 =41+3=6(3)解: (3x+y)2(3xy)2 =(3x+y)(3x-y) =(9x-y) = 81x418x2y2+y4(4)解:(a+3b+c)(a+3bc)=(a+3b) c=a6ab+9bc 56.答案:(1)原式=-12+5-16+18,=-(12+16)+(5+18),=-28+23,=-(28-23),=-5. (2)原式=-356(-4),=10. (3)原式=-24(-12)+(-24)34+(-24)(-13),
38、=12-18+8,=2. (4)原式=4-6+2-1,=(4+2)-(6+1),=6-7,=-1. 57.答案:(1)解:4839+67311157011610(2)解:1802117518010585180106257335 58.答案解:去分母,得3(y+1)=244(2y1),去括号,得9y+3=248y+4,移项,得 9y+8y=24+43,合并同类项,得17y=25,系数化为1,得y=2517 59.答案解:(1)去括号得:104x=3x+4,移项合并得:x=6;(2)去分母得:2x+25x+1=6,移项合并得:3x=3,解得:x=160.答案:(1)解: (34+15678)(24
39、) .=(34)(24)+116(24)+(78)(24) .=18-44+21.=-5.(2)解: 23+|58|+24(3).=-8+3-8.=-13.61.答案:(1)解: |a3| 与 (b2)2 互为相反数 |a3|=(b2)2 a3=0b2=0 a=3b=2 (a)b=(3)2=9 ;(2)解: |a|=3 , |b|=2 ,且ab 0 a=3 , b=2 或 a=3 , b=2 ab=3(2)=5 或 3(2)=5 即 ab=5 或 5 .62.答案:(1)解:-49+91-5+(-9) =-49-5-9+91=-63+91=28(2)解: 0.5+(14)2.75+(12) =
40、 12+(14)234+(12) = 12+(12)+(14)234 =-3(3)解: 23 +( 15 )1+ 13 = 23 + 13 +( 15 )1=1+( 15 )1=-0.2(4)解:2317(7)+(16) =23-17+7-16=23+7-17-16=30-33=-3.63.答案解:原式=15a2b5ab2+4ab212a2b=3a2bab2 , 当a=1,b=12时,原式=32+14=74 64.答案:(1)解:18 16 11 =3+11=14(2)解:6 16 24 =6624=1265.答案:(1)解: 15(8)+(11)12=-15+8-11-12=-30(2)解:
41、 (2312)30(15)= 1630(5)=5(-5)=-2566.答案:(1)78153(2)9567(3)341911(4)0.215.340.1510 15 67.答案解:由a,b,c在数轴上的位置可知ca0b,2ab0,ca0,原式 (2ab) (bc) (ca) ,2abbcca,3a2b. 68.答案:-50 69.答案:(1)解:原式=23+(-17)+7+(-13) =23+7+(-17)+(-13)=30+(-30)=0(2)解:原式= 24(56)+2418+2434 =-20+3+18=1(3)解:原式= 20+(6) =14(4)解:原式= 1+121312 = 1+
42、2 =3.70.答案:(1)解: 3x7(x1)=32(x+3) 3x7x+7=32x6 4x+2x=37 2x=10 x=5 (2)解: 2x(x+10)=6x 2xx10=6x 5x=10 x=2 (3)解: x+232x12=1 2(x+2)3(2x1)=6 2x+46x+3=6 4x=1 x=14 (4)解: 0.4x+0.90.50.03+0.02x0.03=1 4x+953+2x3=1 3(4x+9)5(3+2x)=15 12x+271510x=15 2x=3 x=32 71.答案解:原式=2a12+4a6(a6)+a12=3a124a12=a12 72.答案解:14(10.5)1
43、32(3)2,=11213(7),=1+76 , =16 73.答案解:原式=14(-8)-(-27)53=-2+45=43. 74.答案解:去分母得:4x1=66x+2,移项合并得:10x=9,解得:x=0.975.答案解:(4a3b2ab)(a6bab)=4a3b2aba+6b+ab=3a+3bab=3(a+b)ab,当a+b=12,ab=6时,原式=312(6)=4276.答案解:原式3x25xx2+2x 2x23x, 当x1时, 原式2+3 5 77.答案解:原式x22x22xy+3xy (x22x2)+(2xy+3xy)x2+xy.78.答案:(1)解:13x=810+12x,108
44、=12x13x,2=16x,x=12(2)解:同时乘12, 4(2y-1)=3(y+2)-12,8y-4=3y+6-12 5y=-2,y=25 79.答案:(1)解:原式1+4-3 =2(2)解:原式-a5a8a6-a7(3)解:原式a2+2a+1-a23a5a+1. 80.答案:(1)解:原式=(-2.4-4.6)+(-3.7+5.7)=-7+2=-5(2)解:原式= 314534+(235+225)=-2 12 +5=2 12(3)解:原式=0-9 (-8+4)= 94(4)解:原式= 351645=22581.答案解:原式= x26x+9+2(x2+5x14)(x24) = x26x+9
45、+2x2+10x28x2+4 = 2x2+4x15 , x2+2x4=0 , x2+2x=4 ,把 x2+2x=4 代入上式,原式=24-15=-7.82.答案:(1)解:原式=5(-3)=-15(2)解:原式=-8 14 +6416=-2+4=2 83.答案解:4+5+(7)=3|4|+|5|+|7|=1616(3)=16+3=19,4、5、7这三个数的和比这三个数绝对值的和小1984.答案:(1)解:150+5(63) =150+5+63=145+63=82(2)解:6(16)(16)8 =616+2=96+2=9885.答案:(1)解:去括号得:53y+1=3, 移项合并得:3y=3,解
46、得:y=1;(2)解:去分母得:8y4=3y+612, 移项合并得:5y=2,解得:y=0.4;(3)解:方程整理得:8x325x+4=1210x, 移项合并得:7x=11,解得:x= 117 86.答案解:解方程 2x35=23x3 ,得x=9把x=9代入 3n14=3(x+n)2n 中得 2n27=14所以 (2n27)2=11687.答案解:原式=-1-14(2-9)=-1-14(-7)=-1+74=34 88.答案解: |a|=1,|b|=2,|c|=3, a=1,b=2,c=3又abca=1,b=2,c=3abc=6或-4 89.答案解:(1)-x3y+2x2y-2xy=-xy(x2
47、-2x+2);(2)a2(x-1)+b2(1-x)=(x-1)(a2-b2)=(x-1)(a+b)(a-b);(3)x2+4x-5=(x-1)(x+5);(4)a2-b2+2a+1=a2+2a+1-b2=(a+1)2-b2=(a+1+b)(a+1-b)90.答案:(1)解:原式=84;(2)解:原式=37;(3)解:原式=297;(4)解:原式=1.3+2.7=4;(5)解:原式=9+14=5;(6)解:原式=124+41=83 91.答案:(1)解:原式 =5+8+(16)=13+(16)=3.(2)解:原式 =12(36)56(36)712(36)=18+30+21=33.(3)解:原式
48、=9+22+6+1=2. 92.答案:(1)解: 112 + 123 + 134 + 120132014 =(1 12 )+( 12 13 )+ ( 13 14 )+( 12013 12014 )=1 12 + 12 13 + 13 14 + 12013 12014 =1 12014 = 20132014 ;(2)解: 113=12(113) , 113+135+157+199101 = 12 ( 113+1315+1517+.+1991101 )= 12 ( 11101 )= 12 100101 = 50101 93.答案:解: 2(5x+1)(2x1)=6 ,10x+22x+1=6 ,10
49、x-2x=6-1-2,8x=3,x=3894.答案解:原式=36233634+36112=2427+3=4895.答案:(1)解: 3(2x1)=52(x+2) 去括号,得:6x-3=5-2x-4,移项,合并同类项,得:8x=4,系数化为1,得:x= 12 (2)解: x52=1+2x+33 去分母,得:3(x-5)=6+2(2x+3),去括号,得:3x-15=6+4x+6,移项,合并同类项,得:-x=27,系数化为1,得:x=-2796.答案:(1)解: (11252416)24 = 11224524241624 =2-5-4=-7(2)解: 32229(32)248(2)(12) =-9-
50、 20994 -48 (12)(12) =-9-5-12=-26.97.答案解:由题意得: (2m6)2+|n+2|=0 , 所以 2m6=0,n+2=0 ,解得 m=3,n=2 ,则方程mx+3n=6即为 3x6=6 ,移项、合并同类项,得3x=12,系数化为1,得x=498.答案解:原式=2x2-54x2-3x2+x+1-3=2x2-20x2+15x2-5x-5+15=-3x2-5x+10当x=-32时原式=-3(-32)2-5(-32)+10=-394+152+10=434 99.答案解:去括号得:4x6=6x2, 移项得:4x6x=62,合并得:2x=4,解得:x=2100.答案:(1)解:108(2)3(4)2(2)108(8)16(2)1013221(2)解:( 34 )(221 13 23 )4( 34 ) 43 ( 34 ) 23 ( 34 )31 12 2 12(3)解:(2)3(3)222 14 8 12 ( 12 )28918.5 14 8(0.5)4826