Complex Numbers And Quadratic Equations question 197

Question: If $ (x+1) $ is a factor of $ x^{4}-(p-3)x^{3}-(3p-5)x^{2} $ $ +(2p-7)x+6 $ , then $ p= $ [IIT 1975]

Options:

A) 4

B) 2

C) 1

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

If $ (x+1) $ is a factor of $ x^{4}-(p-3)x^{3}-(3p-5)x^{2}+(2p-7)x+6 $ , then by putting $ x=-1 $ , we get $ 1+(p-3)-(3p-5)-(2p-7)+6=0 $
Þ $ -4p=-16\Rightarrow p=4 $ .