Given the functions, f(x) = x3 + x2 + 1 and g(x) = -6x2 + 2, perform the indicated operations. When applicable, state the domain restriction.
(f + g)(x).

Options:
1. x3 + 7x2 + 3
2. x3 - 7x2 + 5
3. x3 + 5x2 + 3
4. x3 - 5x2 + 3