Find the roots of quadratic equation 3x2 - 2x - 1= 0 – InterviewSolution

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1.

Find the roots of quadratic equation 3x2 - 2x - 1= 0

Answer»

We write, -2x = -3x + x as 3x² \(\times\)(-1) = - 3x² = (-3x) \(\times\)x

∴ 3x²- 2x - 1 = 0

⇒ 3x² - 3x + x -1 = 0

⇒ 3x(x - 1) + 1(x - 1) = 0

⇒ (x - 1))3x + 1) = 0

⇒ x -1 = 0 or 3x + 1 = 0

⇒ x = 1 or x = -1/3

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

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