Final answer:
To evaluate f(x), substitute the value of x into the function f(x).
Step-by-step explanation:
The given function is f(x) = 1/25 * |5x| + 4x.
To evaluate f(x), we substitute the value of x into the function f(x). For example, if x = 2, f(2) = 1/25 * |5(2)| + 4(2) = 1/25 * 10 + 8 = 0.4 + 8 = 8.4.
Therefore, the value of f(x) depends on the value of x and can be calculated by substituting the value of x into the function.