Ответы и объяснения

2012-04-17T20:48:00+04:00

1/6+1/10+1/15=150/900+90/900+60/900=15/90+9/90+6/90=30/90=1/3

1/6+1/10-1/15=150/900+90/900-60/900=15/90+9/90-6/90=30/90=18/90=1/5

1/3/5=1/15

 

1/2-1/3+1/4-1/5=60/120-40/120+30/120-24/120=50/120-24/120=26/120=13/60

13/60/4=13/240

13/240-1/6=13/240-40/240=-27/240=-9/80

 

1/15

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-9/80