Tính tổng 1+4+5+9+14+23+37+60+97 100+98+96+94+….+2-97-95-93-…-3-1 1-2-3-4+5+6-…-299-300+301+302 gợi ý nhóm (1-2-3-4+5)=0 1-2-3+4+5-6-7+8+

0 bình luận về “Tính tổng 1+4+5+9+14+23+37+60+97 100+98+96+94+….+2-97-95-93-…-3-1 1-2-3-4+5+6-…-299-300+301+302 gợi ý nhóm (1-2-3-4+5)=0 1-2-3+4+5-6-7+8+”

1. 1) 1 + 4 + 5 + 9 + 14 + 23 + 37 + 60 + 97

   = 5 + 5 + 23 + 23 + 97 + 97

   = 2.(5+23+97)

   = 2. 125

   = 250

   2) 100+98+96+94+….+2-97-95-93-…-3-1

   = 100 +(98-97) +(96-95) +(94-93)+…+(2-1)

   = 100 +1+1+1+…+1 (98 : 2 =49 số 1)

   = 100 + 49

   = 149

   3) 1-2-3+4+5-6-7+8+9-…+2012+2013-2014-2015+2016+2017

   = (1-2-3+4) +(5-6-7+8)+….+(2013-2014-2015+2016)+2017

   = 0+0+…+0+2017

   = 2017

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2. Đáp án:

   B 100+ (98-97)+(96-95)+(94-93)+….(2-1)

   =100+111…+1×49

   =100+49=40

   C (1+2-3)+(4+5+6-7)+….(298-299-300+301)+302

   =0+0+….0+302=302

   Mk bt 2 ad

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