初一100道数学计算题及答案解析.docx

1、初一100道数学计算题及答案解析1.25 X (8+10 )=1.25 X8+1.25 X10=10+12.5=22.59123- ( 123+8.8 )=9123-123-8.8=9000-8.8=8991.21.24 X8.3+8.3 X1.76=8.3 X (1.24+1.76)=8.3 X3=24.99999 X1001=9999 X (1000+1 )=9999 X1000+9999 X1=1000899914.8 X6.3-6.3 X6.5 + 8.3 X3.7=(14.8-6.5 ) X6.3 + 8.3X3.7=8.3 X6.3+8.3 X3.78.3 X (6.3 +3.7)

2、=8.3 X10=831.24+0.78+8.76=(1.24+8.76 ) +0.78=10+0.78=10.78933-157-43=933- (157+43 )=933-200=7334821-998=4821-1000+2=3823I32 X125 X25=4 X8X125 X25=(4 X25) X (8X125 )= 100 X1000=1000009048 +268=(2600+2600+2600+1248 ) +26=2600 +26+2600 +26+2600 +26+1248 +269=100+100+100+48=3482881 + 43=(1290+1591 ) + 4

3、34=1290 +43+1591 +43=30+373.2 X42.3 X3.75-12.5 X0.423 X16=3.2 X42.3 X3.75-1.25 X42.3 X1.6=42.3 X(3.2 X3.75-1.25 X1.6)=42.3 X(4X0.8 X3.75-1.25 X4X0.4)=42.3 X(4X0.4 X2X3.75-1.25 X4 X0.4)=42.3 X(4x0.4x7.5-1.25x4x0.4)=42.3 X4 X0.4 X(7.5-1.25)=42.3 X4 X0.4 X6.25=42.3 X(4X2.5)=42371.8+18 +1.5-0.5 X0.3=1.8

4、+12-0.15=13.8-0.15=13.656.5 X8+3.5 X8-47=52+28-47=80-47(80-9.8) X5 分之 2-1.32=70.2X2/5-1.32=28.08-1.32=26.768 X7 分之 4 +1 +(3.2-2.95)=8 X4/7 +1 +0.25=8 X4/7 +4=8/72700 X (506 -499 ) +900=2700 X7+900=18900 +900=2133.02 ( 148.4 -90.85 ) +2.5=33.02 -57.55 +2.5=33.02 -23.02=10(1+11) +5.1=(1 1) +5.1=0 +5.1

5、=018.1 + ( 3-0.299 +0.23 ) X1=18.1 + 1.7X1=18.1 + 1.7=19.8-18+29+-52+60= 19-301+125+301+-75= 50卜1+-1/2+3/4+-1/4= -1-7/2+5/6+-0.5+4/5+19/6= 1.25卜26.54+-6.14+18.54+6.14= -81.125+-17/5+-1/8+-0.6= -3卜98+76+(-87)*2356+(-75)-(8+4+3)5+21*8/2-6-5968/21-8-11*8+61-2/9-7/9-564.6-(-3/4+1.6-4-3/4)1/2+3+5/6-7/122

6、/3-4-1/4*(-0.4)/1/3+222+(-4)+(-2)+4*3-2*8-8*1/2+8/1/8(2/3+1/2)/(-1/12)*(-12)(-28)/(-6+4)+(-1)2/(-2)+0/7-(-8)*(-2)(1/4-5/6+1/3+2/3)/1/218-6/(-3)*(-2)(5+3/8*8/30/(-2)-3(-84)/2*(-3)/(-6)-3x+2y-5x-7y1437 X27 +27 X563 75- (12+18 )+152160 +( 83-79 )X18280 +840 +24 X5325 +13 X(266 250) 85 X(95 1440 +24)588

7、70 汽105 +20 X2) 1437 X27 +27 X56381432 13 X52 + 78) 37.85- (7.85+6.4 ) X30156 X(17.7-7.2) +3 (947 599 ) + 76 X6436 X(913 276 +23) 192 ( 54 + 38) X67 (7.1-5.6 ) X0.9-1.15 +2.5 81432 +(13 X52 +78)5.4 +2.6 X (3.7-2.9 ) +0.62 (947 599 ) +76 X64 60 (9.5 +28.9) +0.18 2.881 F.43 0.24 X3.5 20 X(2.44 1.8)+0.

8、4 + 0.15 28-(3.4 1.25 X2.4) 0.8 X15.5-(3.21 5.79)(31.8 3.2 X4) +5 194 64.8 +1.8 X0.9 36.72 +4.25 X9.9 3.416 + (0.016 X35 ) 0.8 X(10-6.76) +1.2(136+64 ) X (65-345 +23) (6.8-6.8 X0.55)+8.50.12 X 4.8 +0.12 X4.8 (58+37 ) + (64-9 X5)812-700 + (9+31 X11 ) (3.2 X1.5+2.5 ) +1.685+14 X (14+208 +26) 120-36 X4

9、+18+35(284+16 ) X (512-8208 +18) 9.72 X1.6-18.305 +74/7 +1/3 X (3/5-3/10 ) (4/5+1/4 ) +7/3+7/1012.78 0+( 13.4 + 156.6 ) 37.812-700 + (9+31 X11 ) (136+64 ) X (65-345 +23 )3.2 X (1.5+2.5 ) +1.6(6.8-6.8 X0.55) +8.5 (284+16 ) X (512-8208 +18)0.12 X 4.8+0.12X4.8 (3.2X1.5+2.5 ) +1.6120-36 X4 +18+35 10.15-

10、10.75 X0.4-5.75.8 X (3.87-0.13 ) +4.2 X3.74 347+45 X2-4160 +5232.52- (6+9.728 +3.2 ) X2.5 87 (58+37 ) + (64-9 X5)(7.1-5.6 ) X0.9-1.15 +2.5 (3.2X1.5+2.5 ) +1.65.4 +2.6 X (3.7-2.9 ) +0.62 12 X6+ (12-7.2 ) -63.2 X6+ (1.5+2.5 )+1.6 (3.2X1.5+2.5 ) +1.65.8 X (3.87-0.13 ) +4.2 X3.7433.02 ( 148.4 -90.85 ) +

11、2.51)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)(9)(-17/4)+(-10/3)+(+13/3)+(11/3)(10)(-1.8)+(+0.2)+(-1.7)+(0.1)+(+1.8)+(+1.4)(11)(+1.3)-(+17/7) (12)(-2)-(+2/3)(13)|(-7.2)-(-6.3)+(1.1)|(14)|(-5/4)-(-3/4)|-|1-5/4-|-3/4|)(15)(-2

12、/199)*(-7/6-3/2+8/3)(16)4a)*(-3b)*(5c)*1/61.3/7 X 49/9 - 4/32. 8/9 X 15/36 + 1/273.12X5/6 - 2/9 X34.8 X 5/4 + 1/45.6 + 3/8 - 3/8 抬6.4/7 X 5/9 + 3/7 X 5/97.5/2 - ( 3/2 + 4/5 )8.7/8 + ( 1/8 + 1/9 )9.9 X 5/6 + 5/610.卡 X=28+4.43/4 X 8/9 - 1/30.12 x+1.8 X0.9=7.2 (9 5 x)X0.3=1.02 6.411.7 X 5/49 + 3/1412.6

13、 X ( 1/2 + 2/3 )13.8 X 4/5 + 8 X 11/514.31 X 5/6 - 5/615.9/7 - ( 2/7 - 10/21 )16.5/9 X 18 - 14 X 2/717.4/5 X 25/16 + 2/3 X 3/418.14 X 8/7 - 5/6 X 12/1519.17/32 - 3/4 X 9/2420.3 X 2/9 + 1/321.5/7 X 3/25 + 3/722.3/14 X X 2/3+ 1/623.1/5 X 2/3 + 5/624.9/22 + 1/11 + 1/225.5/3 X 11/5 + 4/326.45 X 2/3 + 1/

14、3 X 1527.7/19 + 12/19 X 5/628.1/4 + 3/4 +2/329.8/7 X 21/16 + 1/230.101 X 1/5 - 1/5 X 2131.50 + 160 +40 (58+370 ) + (64-45 )32.120-144 +18+3533.347+45 X2-4160 +5234 (58+37 ) + (64-9 X5)35.95 + (64-45 )36.178-145 +5X6+42 420+580-64 X21 +2837.812-700 + (9+31 X11 ) (136+64 ) X (65-345 +23 )38.85+14 X (1

15、4+208 +26) 39. (284+16 ) X (512-8208 +18)10.120-36 X4+18+3541. (58+37 ) + (64-9 X5)42.(6.8-6.8 X0.55) +8.543.0.12 X 4.8+0.12 X4.844. (3.2X1.5+2.5 ) +1.6 (2) 3.2 X (1.5+2.5 ) +1.645.6-1.6 +4= 5.38+7.85-5.37=46.7.2 +0.8-1.2 X5= 6-1.19 X3-0.43=47.6.5 X (4.8-1.2 X4) = 0.68 X1.9+0.32 X1.948.10.15-10.75 X

16、0.4-5.749.5.8 X (3.87-0.13 ) +4.2 X3.7450.32.52- (6+9.728 +3.2) X2.551.-5+58+13+90+78-(-56)+5052.-7*2-57/(353.(-7)*2/(1/3)+79/(3+6/4 )54.123+456+789+98/(-4)55.369/33-(-54-31/15.5)56.39+3x42/2x(3x8)57.9x8x7/5x(4+6)58.11x22/(4+12/2)59.94+(-60)/101.aA3-2bA3+ab(2a-b)=aA3+2aA2b-2bA3-abA2=aA2(a+2b)-bA2(2b

17、+a)=(a+2b)(aA2-bA2)=(a+2b)(a+b)(a-b)2.(xA2+yA2)A2-4y(xA2+yA2)+4yA2=(xA2+yA2-2y)A23.(xA2+2x)A2+3(xA2+2x)+xA2+2x+3=(xA2+2x)A2+4(xA2+2x)+3=(xA2+2x+3)(xA2+2x+1)=(xA2+2x+3)(x+1)A24.(a+1)(a+2)+(2a+1)(a-2)-12=aA2+3a+2+2aA2-3a-2-12=3aA2-12=3(a+2)(a-2)5.xA2(y+z)A2-2xy(x-z)(y+z)+yA2(x-z)A2=x(y+z)-y(x-z)A2=(xz

18、+yz)A2 =zA2(x+y)A26.3(a+2)A2+28(a+2)-20=3(a+2)-2(a+2)+10=(3a+4)(a+12)7.(a+b)A2-(b-c)A2+aA2-cA2=(a+b)A2-cA2+aA2-(b-c)A2=(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)(xA2+x-1)-2=(xA2+x)(xA2+x-1)-2=(xA2+x)A2-(xA2+x)-2=(xA2+x-2)(xA2+x+1)=(x+2)(x-1)(xA2+x+1)1.3/7 X 49/9 - 4/32.

19、 8/9 X 15/36 + 1/273.12X5/6 - 2/9 X34.8 X 5/4 + 1/45.6 + 3/8 - 3/8 抬6.4/7 X 5/9 + 3/7 X 5/97.5/2 - ( 3/2 + 4/5 )8.7/8 + ( 1/8 + 1/9 )9.9 X 5/6 + 5/610.卡 X=28+4.43/4 X 8/9 - 1/30.12 x+1.8 X0.9=7.2 (9 5 x)X0.3=1.02 6.411.7 X 5/49 + 3/1412.6 X ( 1/2 + 2/3 )13.8 X 4/5 + 8 X 11/514.31 X 5/6 - 5/615.9/7 -

20、 ( 2/7 - 10/21 )16.5/9 X 18 - 14 X 2/717.4/5 X 25/16 + 2/3 X 3/418.14 X 8/7 - 5/6 X 12/1519.17/32 - 3/4 X 9/2420.3 X 2/9 + 1/321.5/7 X 3/25 + 3/722.3/14 X X 2/3+ 1/623.1/5 X 2/3 + 5/624.9/22 + 1/11 + 1/225.5/3 X 11/5 + 4/326.45 X 2/3 + 1/3 X 1527. 7/19 + 12/19X 5/628.1/4 + 3/4 +2/329.8/7 X 21/16 + 1

21、/230.101 X 1/5 - 1/5 X 2131.50 + 160 +40 (58+370 ) + (64-45 )32.120-144 +18+3533.347+45 X2-4160 +5234 (58+37 ) + (64-9 X5)35.95 + (64-45 )36.178-145 +5X6+42 420+580-64 X21 +2837.812-700 + (9+31 X11 ) (136+64 ) X (65-345 +23 )38.85+14 X (14+208 +26)39. (284+16 ) X (512-8208 +18)10.120-36 X4+18+3541.

22、(58+37 ) + (64-9 X5)42.(6.8-6.8 X0.55) +8.543.0.12 X 4.8+0.12 X4.844. (3.2X1.5+2.5 ) +1.6 (2) 3.2 X (1.5+2.5 ) +1.645.6-1.6 +4= 5.38+7.85-5.37=46.7.2 +0.8-1.2 X5= 6-1.19 X3-0.43=47.6.5 X (4.8-1.2 X4) = 0.68 X1.9+0.32 X1.948.10.15-10.75 X0.4-5.749.5.8 X (3.87-0.13 ) +4.2 X3.7450.32.52- (6+9.728 +3.2)

23、 X2.551.-5+58+13+90+78-(-56)+5052.-7*2-57/(353.(-7)*2/(1/3)+79/(3+6/4 )54.123+456+789+98/(-4)55.369/33-(-54-31/15.5)56.39+3x42/2x(3x8)57.9x8x7/5x(4+6)58.11x22/(4+12/2)59.94+(-60)/101.aA3-2bA3+ab(2a-b)=aA3+2aA2b-2bA3-abA2=aA2(a+2b)-bA2(2b+a)=(a+2b)(aA2-bA2)=(a+2b)(a+b)(a-b)2.(xA2+yA2)A2-4y(xA2+yA2)+4

24、yA2=(xA2+yA2-2y)A23.(xA2+2x)A2+3(xA2+2x)+xA2+2x+3=(xA2+2x)A2+4(xA2+2x)+3=(xA2+2x+3)(xA2+2x+1)=(xA2+2x+3)(x+1)A24.(a+1)(a+2)+(2a+1)(a-2)-12=aA2+3a+2+2aA2-3a-2-12=3aA2-12=3(a+2)(a-2)5.xA2(y+z)A2-2xy(x-z)(y+z)+yA2(x-z)A2=x(y+z)-y(x-z)A2=(xz+yz)A2=zA2(x+y)A26.3(a+2)A2+28(a+2)-20=3(a+2)-2(a+2)+10=(3a+4)(a+12)7.(a+b)A2-(b-c)A2+aA2-cA2=(a+b)A2-cA2+aA2-(b-c)A2=(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)(xA2+x-1)-2=(xA2+x)(xA2+x-1)-2=(xA2+x)A2-(xA2+x)-2=(xA2+x-2)(xA2+x+1)=(x+2)(x-1)(xA2+x+1)