The remainder, when x3−4x2+5x−1 is divided by 2x+1 is
A) −218
B) 227
The correct option is B: 227
According to remainder theorem, If a polynomial p(x) is divided by a binomial (x−a) then the remainder obtained is p(a).
so, 2x+1=0
x=−12
so, p(−12) will be the remainder.
Let p(x)=x3−4x2+5x−1
Put x=−12 in the above polynomial p(x)
p(−12)=(−12)3−4(−12)2+5(−12)−1
=−18−4(14)−52−1
=−18−52−2
=−1−20−168
=−378
Therefore, the remainder is −378.