Hi!
First make the denominators the same.
[tex] \frac{8}{20} + \frac{10}{20} = ?[/tex]
Add the numerators
[tex] \frac{8}{20} + \frac{10}{20} = \frac{18}{20}[/tex]
Simplify to get your answer
The answer is [tex] \frac{9}{10} [/tex]
Hope this helps! :)