Examveda

If (x - 1) and (x + 3) are the factors of x2 + k1x + k2 then-

A. k1 = -2, k2 = -3

B. k1 = 2, k2 = -3

C. k1 = -2, k2 = 3

D. k1 = 2, k2 = 3

Answer: Option B

Solution (By Examveda Team)

$$\eqalign{ & \therefore {\text{When}}\left( {x - 1} \right) = 0 \cr & x = 1 \cr & {x^2} + {k_1}x + {k_2}{\text{ }} = 0 \cr & \Rightarrow 1 + {k_1} + {k_2}{\text{ }} = 0 \cr & \Rightarrow {k_1} + {k_2} = - 1\,.......(i) \cr & {\text{When}}\left( {x + 3} \right) = 0 \cr & x = - 3 \cr & 9 - 3{k_1} + {k_2}{\text{ }} = 0 \cr & \Rightarrow - 3{k_1} + {k_2}{\text{ }} = - 9\,.......(ii) \cr & {\text{From equation (i) and (ii)}} \cr & {k_1} = 2,\,\,\,\,\,\,{\text{ }}{k_2} = - 3 \cr} $$

This Question Belongs to Arithmetic Ability >> Algebra

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