If f(x) = k(x - k) and k is a constant, what is the value of f(6) - f(2), in terms of k? Choose the correct choice from the following choices: A) 1 B) 4k C) 7k - 1 D) k^2 + k E) k^2 - k
First, distribute f(x). k(x - k) = kx - k^2. Now evaluate f(6) and f(2):   f(6) = k(6) - k^2 = 6k - k^2   f(2) = 2k - k^2   Answer 4k
<result>B</result>
If f(x) = k(x - k) and k is a constant, what is the value of f(6) - f(2), in terms of k?