will +rep the first person to get each question right

1. Determine the domain of the function represented by the given equation.
f(x) = x^2 + 9


2. Determine the domain of the function represented by the given equation.
f(x) = 7/(x + 3)


3. Find the values of a in the domain of f for which f(a) equals the given number. (If there is no solution, enter NO SOLUTION.)
f(x) = x^2 − 2x − 19; f(a) = −16


4. Find the zeros of f.
f(x) = 10 − 6x