To add to rational numbers you can follow the next steps:
[tex]\begin{gathered} \frac{3}{4}+\frac{1}{10}=\frac{3\times10+4\times1}{4\times10} \\ \Rightarrow\frac{30+4}{40}=\frac{34}{40} \end{gathered}[/tex]Now, to simplify you can start by dividing both numbers by 2:
[tex]\frac{34/2}{40/2}=\frac{17}{20}[/tex]As 17 is a prime number, this is the final result: 17/20.