Answer:
The answer is 8.
Step-by-step explanation:
We need to use the quadratic formula, that is ax2+bx+c=0
Where
For the given equation x2+5x-104=0 we have
a=1, b=5, c= -104
If you solve that, we will have x=-13. x=8, two answers,
The first one, by being negative does not have physical sense (there are no negatives quantities when you measure the length of something)
So we use the anwser x=8