Question

http://prntscr.com/ha0sl3

Answer 1

7|-78?

Answer 2

|- is the radical sign

Answer 3

You can only add if the number inside the radical is the same

Answer 4

So you'd have to simplify both first to see if you can add

Answer 5

2√54 -> 2( √6 * √9) -> 2 * 3 √6 = 6√6

Answer 6

And 5√24 -> 5 (√4 * √6) -> 5 * 2 √6 = 10√6

Answer 7

So now that it is simplified, you can change 2√54 + 5√24 to 6√6 + 10√6
Now all you have to do is add the outside numbers which are 6 + 10 and leave √6 the same
6 + 10 = 16
16√6