Question

RESPECTED EXPERTS, Please help me in this question
If zeroes of the polynomial f(x)=x3-12x2+39x+a are in arithmetic progressions, then find 'a'.
Please answer as early as possible. REALLY URGENT.

Answer 1

f(x)=x3-12x2+39x+a
Let f(x)=0 Then,
f(0)= (0)³-12*2+39(0)+a
f(0)= 0-24+0+a
f(0)=24+a
-24=a