Find the two roots of equation, x² + 7x + 12 = 0?

Question

Question

This question was previously asked in

NPCIL Stipendiary Trainee (Category-II) Official Paper (Held On: 11 Jun 2019)

Answer 1

Given:

Equation: x² + 7x + 12 = 0

Formula used:

Quadratic formula: $x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

Calculations:

For the equation x² + 7x + 12 = 0:

a = 1, b = 7, c = 12

Discriminant: $b^2 - 4ac$

⇒ (7)² - 4×1×12

⇒ 49 - 48

⇒ 1

Using the quadratic formula:

⇒ $x = \dfrac{-7 \pm \sqrt{1}}{2×1}$

⇒ $x = \dfrac{-7 \pm 1}{2}$

Roots:

x = $\dfrac{-7 + 1}{2}$ = -3

x = $\dfrac{-7 - 1}{2}$ = -4

∴ The correct answer is option (2).

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