1)1/6+3/6= 2)3/7+2/7= 3)1/4+3/8= 4)5/12+7/15= 5)4цел5/6+2цел3/8= 6)3цел+2цел1/3=

1)1/6+3/6=2/3
1/6+3/6=(1+3)/6=4/6=2/3
2)3/7+2/7=5/7
3/7  +  2/7 = (3  +  2)/7 =  5/7
3)1/4+3/8=5/8
НОК(4,8)  = 8
8:4 = 2     8:8 = 1     
(1 × 2  +  3 × 1)/8 = (2  +  3)/8 =  5/8
5/8 = 0.625
4)5/12+7/15=53/60
НОК(12,15)  = 60 
60:12 = 5     60:15 = 4     
(5 × 5  +  7 × 4)/60 = (25  +  28)/60 =  53/60
53/60 = 0.8833333333
5)4Цел5/6+2Цел3/8=7 5/24
4 5/6  +  2 3/8 = 29/6  +  19/8 
НОК(6,8)  = 24
24:6 = 4     24:8 = 3     
(29 × 4  +  19 × 3)/24 = (116  +  57)/24 =  173/24 = 7 5/24
7 5/24 = 7.2083333333
6)3Цел+2Цел1/3=5 1/3
3  +  2 1/3 = 3  +  7/3, 
НОК(1,3)  = 3(3 × 3  +  7 × 1)/3 = (9  +  7)/3 =  16/3 = 5 1/3
5 1/3 = 5.3333333333