For these problems, subtract the given functions and indicate the domain of the difference.

1. f(x) = (√x - 6) and g(x) = x - 6

2. f(x) = 3/(x + 2) and
g(x) = - 5/(x + 2)

3. f(x) = x^2 + 3x + 1 and g(x) = 2x^2 - 4x - 1

4. f(x) = 7x - 8 and
g(x) = -11x - 3