Question

помоги пожалуйста дам 30 баллов

Answer 1

1/2-1/3=3/6-2/6=1/6
1/3-1/4=4/12-3/12=1/12
1/4-1/5=5/20-4/20=1/20
1/5-1/6=6/30-5/30=1/30
1/6-1/7=7/42-6/42=1/42
1/7-1/8=8/56-7/56=1/56


1/6+1/12+1/20+1/30+1/42+1/56=(1/6+1/12)+(1/20+1/30)+1/42+1/56=
(1/12+2/12)+(3/60+2/60)+1/42+1/56=
3/12+5/60+1/42+1/56=
3/12+1/12+1/42+1/56=




4/12+1/42+1/56=1/3+1/42+1/56=14/42+1/42+1/56=15/42+1/56=5/14+1/56=20/56+1/56=21/56