Answer:
116 / 45
Explanation:
To add fractions with unlike denominators, we need to find their common denominator.
One way to do this is by finding the least common multiple (LCM) of the denominators.
The LCM of 3, 5, 9 and 15 is 45.
We then convert each fraction so that its denominator is 45:
1/3 = 15/45
3/5 = 27/45
7/9 = 35/45
13/15 = 39/45
Now we can add the fractions:
15/45 + 27/45 + 35/45 + 39/45
To simplify, we can add the numerators and keep the common denominator:
(15 + 27 + 35 + 39) / 45
Which gives us:
116 / 45
Therefore, the sum of the fractions 1/3 + 3/5 + 7/9 + 13/15 is, 116 / 45.