С, 6 класс: 1/2 + 1/3 = 3/5 - 1/10 = 1/12 + 5/6 = 1/3 + 1/4 = 1/3 + 2/5 = 1/2 - 1/4 = 8/7 - 1 = 1/4 - 1/5 = 1/2 + 3/7 = 3/4 - 1/8 = 1/5 + 1/6 = 4/15 + 2/5 = 7/10 - 1/2 = 1/3 - 1/4 = да-да-да, бла-бла-бла, я туп. но , соберитесь с мыслями и мне, я этого

1/2 + 1/3 = 3/6+2/6=5/6
3/5 - 1/10 =6/10-1/10=5/10=0,5
1/12 + 5/6 =1/12+10/12=11/12
1/3 + 1/4 =4/12+3/12=7/12
1/3 + 2/5 =5/15+6/15=11/15
1/2 - 1/4 =2/4-1/4=1/4=0,25
8/7 - 1 =8/7-7/7=1/7
1/4 - 1/5 =5/20-4/20=1/20=0,05
1/2 + 3/7 =7/14+6/14=13/14
3/4 - 1/8 =12/16-2/16=11/16
1/5 + 1/6 =6/30+5/30=11/30
4/15 + 2/5 =4/15+6/15=10/15=2/3
7/10 - 1/2 =7/10-5/10=2/10=0,2
1/3 - 1/4 =4/12-3/12=1/12