Question

Solve x^2+2x+7=0 using the quadratic formula.

Answer 1

Answer:

$x=-1\pm \sqrt{6}i$

Step-by-step explanation:

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

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

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

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

$x=\frac{-2\pm\sqrt{-1*24}}{2}$

$x=\frac{-2\pm\sqrt{-1}\sqrt{24}}{2}$

$x=\frac{-2\pm i\sqrt{4*6}}{2}$

$x=\frac{-2\pm i\sqrt{4}\sqrt{6}}{2}$

$x=\frac{-2\pm2i\sqrt{6}}{2}$

$x=-1\pm \sqrt{6}i$