We need to calculate the following sum:
![(8)/(15)+(7)/(25)](https://img.qammunity.org/2023/formulas/mathematics/college/51gwuyu9u0i9gk9dwn3umx4nh6ut6m95zb.png)
The first step is to calculate the least common multiplier between the two denominators. This is done below:
![\begin{gathered} 15=3\cdot5 \\ 25=5\cdot5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/6pz1p7vqk52dol1ik35j4sqan7voxj2e7n.png)
We broke down the two denominators into their factors, now we need to multiply the factors that are unique. This is done below:
![\text{LCM}=3\cdot5\cdot5=75](https://img.qammunity.org/2023/formulas/mathematics/college/vdum2jf7m9fe0hohsh712e8tb8uh50r5vn.png)
Now we have to replace the denominators by 75 and calculate new numerators. The new numerators must be calculated as follows:
1 - Divide the LCM by the old denominator
2 - Multiply the result of 1 by the old numerator.
This is done below:
![\begin{gathered} (5\cdot8)/(75)+(3\cdot7)/(75) \\ (40)/(75)+(21)/(75) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/fp6nia1yr4ayqtq6i5wnqorlxqd7tqbg7f.png)
Since both fractions have their denominators with the same value, we can just directly add them.
![(40+21)/(75)=(61)/(75)](https://img.qammunity.org/2023/formulas/mathematics/college/tyd1iuuc4nr22ynvi2mi1o4g4u19lj2tf3.png)
The fraction is already in its most reductable form, therefore the answer is 61/75.