Question

Solve the following quadratic equation:

9x² – 3x – 2 = 0

Answer 1

We write, –3x = 3x – 6x as 9x² × (–2) = –18x² = 3x × (–6x) 

∴ 9x² – 3x – 2 = 0

⇒ 9x² + 3x – 6x – 2 = 0

⇒ 3x(3x + 1) – 2(3x + 1) = 0 

⇒ (3x + 1)(3x – 2) = 0 

⇒ 3x + 1 = 0 or 3x – 2 = 0 

⇒ `x = -1/3` or `x = 2/3` 

Hence, the roots of the given equation are `-1/3` and `2/3`.