How do you solve $2x^2 – 8x = –7$ using the quadratic formula?

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Answer 1 · 2016-02-29T17:11:30

The solutions are:
$x = (4+sqrt(2))/2$
$x = (4-sqrt(2))/2$

$2x^2 -8x+7=0$

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

$a=2, b=-8, c=7$

The Discriminant is given by:

$Delta=b^2-4*a*c$

$= (-8)^2-(4* 2 * 7)$

$= 64- 56 =8$

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

$x = (-(-8)+-sqrt(8))/(2*2) = (8+-2sqrt(2))/4$

$=( 2(4+-sqrt(2)))/4$

$=( cancel2(4+-sqrt(2)))/cancel4$

$=(4+-sqrt(2))/2$

The solutions are:
$x = (4+sqrt(2))/2$
$x = (4-sqrt(2))/2$

How do you solve 2x^2 – 8x = –72x^2 – 8x = –7 using the quadratic formula?