The first four terms, in ascending powers of x, of the binomial expansion of (1 + kx)^n are
1 + Ax + Bx2 + Bx3 + …,
where k is a positive constant and A, B and n are positive integers.
(a) By considering the coefficients of x2 and x3, show that 3 = (n – 2) k. (4 MARKS)
Given that A = 4,
(b) find the value of n and the value of k. (4 MARKS)
PLZ SHOW YOUR WORKING