Let P(x)=(k+1)x+(3−2k), where k is a real number.
(i) Determine the value of k for which x=4 is the zero of P(x).
(ii) Using this value of k, write the equation of the line y=P(x) and find its y-intercept.
(iii) Confirm algebraically that the point (4,0) lies on the line obtained in part (ii).