Question

In the quadratic equation 2x² + 8x + 10= 0?

Answer 1

$\sf{\underline{\boxed{\green{\large{\bold{ Question}}}}}}$

• solve the equation using formulae $\sf 2x^2 + 8x + 10 = 0$

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$\sf{\underline{\boxed{\green{\large{\bold{ Solution}}}}}}$

$\sf\implies 2x^2 + 8x + 10 = 0$

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• compare the eq with $\sf{\underline{\bold{ax^2 + bx + c = 0 }}}$

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☯ a = 2

☯ b = 8

☯ c = 10

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• now :-

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$\sf{\underline{\boxed{\pink{\large{\mathfrak{x = \dfrac{ - b \pm \sqrt D }{2a }}}}}}}$

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$\sf{\underline{\boxed{\pink{\large{\mathfrak{ D = b^2 - 4ac }}}}}}$

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• finding value of D.

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$\sf\implies D = b^2 - 4ac$

$\sf\implies D = (8)^2 - 4 \times 2 \times 10$

$\sf\implies D = 64 - 80$

$\sf\implies D = - 16$

$\sf{\underline{\boxed{\blue{\large{\bold{ D = - 16}}}}}}$

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• putting values in the eq.

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$\sf\implies x = \dfrac{ -b \pm\sqrt D }{2a}$

$\sf\implies x = \dfrac{ -( 8 ) \pm\sqrt {-16} }{2\times 2 }$

$\sf\implies x = \dfrac{ -8 \pm -4 }{4}$

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✒$\sf x = \dfrac{ - 8 + 4 }{ 4 }$

$\implies x = \dfrac {-4}{4}$

$\implies x = -1$

$\sf{\underline{\boxed{\purple{\large{\bold{ x = - 1 }}}}}}$

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✒$\sf x = \dfrac{ - 8 - 4 }{ 4 }$

$\implies x = \dfrac {-12}{4}$

$\implies x = -3$

$\sf{\underline{\boxed{\purple{\large{\bold{ x = -3 }}}}}}$

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$\sf{\underline{\boxed{\purple{\large{\bold{ x = -1 \: or \:-3 }}}}}}$