To find \( (f + g)(x) \), we need to add the functions \( f(x) \) and \( g(x) \).
Given: \[ f(x) = x^2 + 7x + 10 \] \[ g(x) = x + 5 \]
Now, we can find \( (f + g)(x) \) by adding \( f(x) \) and \( g(x) \):
\[ (f + g)(x) = f(x) + g(x) \] \[ = (x^2 + 7x + 10) + (x + 5) \]
Now, let's combine like terms:
- Combine \( x^2 \) terms: \( x^2 \)
- Combine \( x \) terms: \( 7x + x = 8x \)
- Combine constant terms: \( 10 + 5 = 15 \)
Putting it all together, we get:
\[ (f + g)(x) = x^2 + 8x + 15 \]
Thus, the result expressed as a polynomial in simplest form is:
\[ \boxed{x^2 + 8x + 15} \]