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

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Answer 1 · 2016-05-21T12:00:57

The solutions for the quadratic equation are:
$color(blue)(x=7$
$color(blue)(x=1$

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

The equation is of the form $color(blue)(ax^2+bx+c=0$ where:
$a=1, b=-8, c=7$

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

$= (-8)^2-(4 * 1 * 7)$

$= 64 -28 =36$

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

$x = (-(-8)+-sqrt(36))/(2*1) = (8+-6)/2$

$x = ( 8 + 6) /2 = 14/2 = 7$

$x = ( 8 - 6) /2 = 2/2 = 1$

How do you solve y = x^2 − 8x + 7 y = x^2 − 8x + 7 using the quadratic formula?