pls clear my doubt..

Question

www.sarthaks.com/714797/please-solve-this-question

I have one doubt that in the answer ( click on that link) 1/4 and 1/3 are used to solve the question. But in book it has given that only the factors of constant can be used to solve that question. NOTE - 1/3 and 1/4 are not the factors of 1.

Answer 1

Factor Theorem Procedure

Step 1 : If f(-c)=0, ( x+ c) is a factor of the polynomial f(x).

Step 2 : If p(d/c)= 0, (cx-d) is a factor of the polynomial f(x).

Step 3 : If p(-d/c)= 0, (cx+d) is a factor of the polynomial f(x).

Step 4 : If p(c)=0 and p(d) =0, then (x-c) and (x-d) is a factor of the polynomial.

If p(d/c)= 0, (cx-d) is a factor of the polynomial f(x).