As we can see on the given graph, the domain of function F goes from x=3 to x=12. Then, the domain of F is
[tex]\lbrack3,12\rbrack[/tex]
On the other hand, the domain of G goes from x=2 to x=11. Then, the domain of G is
[tex]\lbrack2,11\rbrack[/tex]
Then, from the above results, we can see that the domain of F+G is the intersection of the domain of F and G, that is
[tex]\lbrack3,11\rbrack[/tex]
