Answer is 7
Given expression is (1+a+a2+a3)(1+a4)
= 1 + a + a2 ... a7
If 1 + a + a2 + a3..... an =(1+a)(1+a2)(1+a4) then n is equal to ____ ??
It depends on the value of a
if u take a =0 then it is not possible
if a=1 then n=8
if a=-1 then n=any odd number
so it all depends on a!