How do you solve $x^2-2x+7=-4$ using the quadratic formula?

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Answer 1 · 2016-11-11T15:13:51

$x=1+-isqrt10$

(There are no real solutions.)

Make one side equal to zero by adding 4 to each side:
$x^2-2x+7=-4$
$x^2-2x+11=0$

Quadratic formula:
$x=(-b+-sqrt(b^2-4ac))/(2a)$
$x=(2+-sqrt[(-2)^2-(4)(1)(11)])/(2*1)$

Simplify:
$x=(2+-sqrt(-40))/(2)$
$x=(2+-2isqrt10)/2$
$x=1+-isqrt10$

How do you solve x^2-2x+7=-4x^2-2x+7=-4 using the quadratic formula?