Find the value of $x$ : $x^{2} + 2 x - 7$

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Solution

Given,

$x^{2} + 2 x - 7 = 0$

$a = 1, b = 2, c = - 7$

$x = \frac{- b \pm \sqrt{b^{2} - 4 a c}}{2 a}$

$x = \frac{- 2 \pm \sqrt{2^{2} - 4 (1) (- 7)}}{2 (1)}$

$= \frac{- 2 \pm 4 \sqrt{2}}{2}$

$= - 1 \pm 2 \sqrt{2}$

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Similar questions

x = - 3

x^{2} + 2 x + 1

Find the value of the following expressions, when x = − 1:

(i) 2x − 7 (ii) − x + 2 (iii) x² + 2x + 1

(iv) 2x² − x − 2

\frac{2 x}{x^{2} - 2 x + 1} = \frac{1}{2}

{(x - \frac{1}{x})}^{2}

\int \frac{2 x + 1}{\sqrt{x^{2} + x + 1}} d x

\frac{x^{2} + 34 x - 71}{x^{2} + 2 x - 7}

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