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