4) 3/7 + 1/28 + 11/35

First, find a common denominator for all three fractions: 7, 28, and 35. Since 7, 28, and 35 are multiples of each other, their least common multiple is 140.

Now, convert each fraction to have a denominator of 140:
3/7 = 60/140
1/28 = 5/140
11/35 = 44/140

Now add the fractions together:
60/140 + 5/140 + 44/140 = (60 + 5 + 44)/140 = 109/140

So, 3/7 + 1/28 + 11/35 = 109/140

5) 5/8 + 1/6 + 7/12

First, find a common denominator for all three fractions: 8, 6, and 12. Since 8, 6, and 12 are multiples of each other, their least common multiple is 24.

Now, convert each fraction to have a denominator of 24:
5/8 = 15/24
1/6 = 4/24
7/12 = 14/24

Now add the fractions together:
15/24 + 4/24 + 14/24 = (15 + 4 + 14)/24 = 33/24

Since 33 is bigger than 24, we can simplify the fraction by dividing both the numerator and denominator by their greatest common factor, which is 3:
33/24 = 11/8

So, 5/8 + 1/6 + 7/12 = 11/8