Answer :
I'm pretty sure it's 7/13 because u do not change the denominators when u are adding they stay the same. And 2+5 is 7 the answer is c 7/13
[tex]\sf\dfrac{2}{13}+\dfrac{5}{13}[/tex]
Add the numerators and keep the denominator:
[tex]\sf\dfrac{2+5}{13}\rightarrow\dfrac{7}{13}[/tex]
Add the numerators and keep the denominator:
[tex]\sf\dfrac{2+5}{13}\rightarrow\dfrac{7}{13}[/tex]