The missing factor is found as follows:
- we have to find two monomials that, when multiplied together, gives:
and, when added together gives:
Now, such two monomials are: 15s and 8s
since:
and:
Therefore, we can rewrite the left-hand side of the equation as:
We can now find the missing factor by factorization, as follows:
Therefore, the missing factor is: (s + 3)