Question

find sum roots of the quadratic equation x²+2x+7=0​

Answer 1

Step-by-step explanation:

$x²+2x+7=0$

Comparing the equation with ax² + bx + c = 0,

$a = 1 , \: b = 2 \: \: and \: \: c = 7$

$a \times c = 1 \times 7 = 7$

Substituting the value in the formula -

$\bold{x = \frac{ - b± \sqrt{ {b}^{2} - 4ac } }{2a} }$

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

$\bold{x = \frac{ - 2± \sqrt{4 - 4(7)}}{2} }$

$\bold{x = \frac{ - 2± \sqrt{4 - 28} }{2} }$

$\bold{x = \frac{ - 2± \sqrt{ - 24} }{2} }$

On taking the (+) sign,

$\bold{x = \frac{ - 2 + \sqrt{ - 24} }{2} }$

On taking the (–) sign,

$\bold{x = \frac{ - 2 - \sqrt{ - 24} }{2} }$

I hope it is helpful