To find the missing factor, divide 7s^2 + 19s + 10 by s+2. I prefer to do this using synthetic division:
______________
-2 / 7 19 10
-14 -10
----------------------------
7 5 0
Because theres a zero remainder, -2 is a root of the given equation, and (x+2) is a factor. From the coefficients 7 5 we know that the other factor is (7x+5) (answer)
Check this by mult. (7s+5) and (s+2) together. You must get 7s^2+19s+10.