if Δ = |(x - 2, 2x - 3, 3x - 4) (2x - 3, 3x - 4, 4x - 5) (3x - 5, 5x - 8, 10x - 17) Ax^3 + Bx^2 + Cx + D, then B + C is equal to :

Question

if Δ = \(\begin{vmatrix} x-2&2x-3&3x-4\\2x- 3&3x-4&4x-5\\3x-5&5x-8&10x-17\end{vmatrix}\) = Ax³ + Bx² + Cx + D, then B + C is equal to :

(1) –1 

(2) 1 

(3) –3 

(4) 9

Answer 1

(3) -3

= –3(x – 1)² (x – 2) = –3x³ + 12x² – 15x + 6 

\(\therefore\) B + C = 12 – 15 = –3