To complete the square for the polynomial \( s^2 + 14s \), we want to find a number to add that will make it a perfect square.
- Start with the coefficient of \( s \), which is 14.
- Divide this coefficient by 2:
\[ \frac{14}{2} = 7 \] - Square this result:
\[ 7^2 = 49 \] - Therefore, to complete the square, you need to add 49 to the polynomial.
So, the completed polynomial is: \[ s^2 + 14s + 49 \]
This can be factored as: \[ (s + 7)^2 \]
Thus, the number that makes the polynomial a perfect-square quadratic is 49.