Consider the quadratic equation x2+8x+9=0. Which of the following is the correct form after substituting a, b, and c into the Quadratic Formula?

Question

asked Dec 20, 2022 228k views

2 Answers

Netpoetica · Answer 1 · 2022-12-26T11:08:36+0000

Answer:

x²+8x+9=0

Comparing above equation with ax²+bx +c

we get

a=1

b=8

c=9

quadratic equation is

$x = \frac{ - 8± \sqrt{ {8}^(2) - 4×1×9} }{2*1}$

x = ( -8± √( 64-36) )/(2)

2x+8=±
$\sqrt{ {28}}$

taking + ve

2x=
$\sqrt{ {28}}$ -8

x=
$2\sqrt{ {7}}$ -8/2

x=
$\sqrt{ {7}}$ -4

taking -ve

2x=-
$\sqrt{ {28}}$ -8

x=-
$2\sqrt{ {7}}$ -8/2

x=-
$\sqrt{ {7}}$ -4