Question

If x = 3 is a solution of the equation 3x² + (k – 1)x + 9 = 0 then k = ?

पर्याय

• 11

• –11

• 13

• –13

Answer 1

–11

Explanation:

It is given that x = 3 is a solution of 3x² + (k – 1)x + 9 = 0; therefore, we have:  

3(3)² + (k – 1) × 3 + 9 = 0 

⇒ 27 + 3(k – 1) + 9 = 0 

⇒ 3(k – 1) = –36 

⇒ (k – 1) = –12 

⇒ k = –11