# The roots of quadric equations 6x2 - 5x - 21 = 0 are

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The roots of quadric equations 6x2 - 5x - 21 = 0 are
1. $-\frac{7}{3}, -\frac{3}{2}$
2. $\frac{7}{3}, \frac{3}{2}$
3. $\frac{7}{3}, -\frac{3}{2}$
4. $-\frac{7}{3}, \frac{3}{2}$

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Correct Answer - Option 3 : $\frac{7}{3}, -\frac{3}{2}$

Given

6x2 - 5x - 21 = 0

Concept used

Calculation

⇒ 6x2 - 14x + 9x - 21 = 0

⇒ 2x(3x - 7) + 3(3x - 7)

⇒ (2x + 3) (3x - 7)

Where 2x + 3 = 0 and 3x - 7 = 0

⇒ 2x + 3 = 0

⇒ 2x = -3

⇒ x = -3/2

⇒ 3x - 7 = 0

⇒ 3x = 7

⇒ x = 7/3

Two root equations are x = -3/2 and 7/3