How do you solve $x^{2} - 3 x = - 7$ $x^2 -3x = -7$ ?

Question

1698 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-08-11T17:14:28

The solutions are:
$x = \frac{(3) + \sqrt{- 19}}{2}$ $color(green)(x = ((3)+sqrt(-19))/(2$

$x = \frac{(3) - \sqrt{- 19}}{2}$ $color(green)(x = ((3)-sqrt(-19))/(2$

$x^{2} - 3 x + 7 = 0$ $x^2−3x+7=0$

The equation is of the form $a x^{2} + b x + c = 0$ $color(blue)(ax^2+bx+c=0$ where:

$a = 1, b = - 3, c = 7$ $a=1, b=-3, c=7$

The Discriminant is given by:
$Delta=b^2-4*a*c$

$= (-3)^2-(4*1*7)$

$= 9-28=-19$

The solutions are found using the formula
$x=(-b+-sqrtDelta)/(2*a)$

$x = (-(-3)+-sqrt(-19))/(2$

The solutions are:
$color(green)(x = (3+sqrt(-19))/(2$

$color(green)(x = (3-sqrt(-19))/(2$

How do you solve x^2 -3x = -7x2−3x=−7x^2 -3x = -7?