maths 題

2006-11-27 3:44 am

1+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20-1-2-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20=?

回答 (9)

2006-11-27 3:48 am

✔ 最佳答案

答案：－1
因為加數過程中，＋１係重復左，而減數中，－２重復，所以就係咁！～

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2006-11-27 11:49 pm

1+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20-1-2-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20= -1

答: -1

參考: 頭腦

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2006-11-27 3:56 am

(1+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20)-(1+2+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20)
=211-212
=-1

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2006-11-27 3:55 am

1+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20-1-2-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20=-1

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2006-11-27 3:52 am

1+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20-1-2-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20
=1+210-210
=1

參考: 運用三角形數概念

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2006-11-27 3:51 am

=1+N(N+1)/2 -2-[N(N+1)]
=1+20(20+1)/2 -2-[20(20+1)]
=1+210-2-210
=1-2
=-1

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2006-11-27 3:49 am

-1..

(1+1)+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20-1-2-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20=-1

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2006-11-27 3:48 am

(1-1+2-2+3-3+4-4+5-5+6-6+7-7+8-8+9-9+10-10+11-11+12-12+13-13+14-14+15-15+16-16+17-17+18-18+19-19+20-20)=0再計(1-2)=-1
答案:0+(-1)=-1

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2006-11-27 3:48 am

The answer is -1.

參考: me

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