求教一题速算题（1/7）+（3/8）+（7/36）+（29/56）+（37/63）+（41/72）+（53/77）+（2
1个回答
（1/7）+（3/8）+（7/36）+（29/56）+（37/63）+（41/72）+（53/77）+（29/84）+（3/88）
=1/7+3/8+7/36+(21/56+8/56)+(28/63+9/63)+(9/72+32/72)+(11/77+42/77)+(21/84+8/84)+(11/88-8/88)
=1/7+3/8+7/36+3/8+1/7+4/9+1/7+1/8+4/9+1/7+6/11+1/4+2/21+1/8-1/11
=(1/7+1/7+1/7+1/7)+(3/8+3/8+1/8+1/8)+(4/36+3/36)+(4/9+4/9)+(6/11-1/11)+1/4+(3/21-1/21)
=4/7+1+1/9+1/12+8/9+5/11+1/4+1/7-1/21
=5/7+2+(1/12+1/4)+5/11-1/21
=5/7+2+1/3+5/11-1/21
=2+5/11+(15/21+7/21-1/21)
=3+5/11
=3又5/11
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