Suppose an investment of $8,200 doubles in value every 7 years. how much is the investment worth after 28 years?

The graph of the function f(x) = (x + 2)(x + 6) is shown below. which statement about the function is true? the function is positive for all real values of x where x > –4. the function is negative for all real values of x where –6 < x < –2. the function is positive for all real values of x where x < –6 or x > –3. the function is negative for all real values of x where x < –2.