Solve by using the quadratic formula?

Question

X to the second power plus 6x equals -9!

Answer 1

I assume - 9!, with exclamination mark is - 9 not 91

Quadratic Formula

x = - 6 ± √b² - 4ac / 2a

x² + 6x - 9 = 0

let

a = 1

b = 6

c = - 9

- - - - - - - -

x = - 6 ± √(6)² - 4(1)(- 9) / 2(1)

x = - 6 ± √36 - (- 36) / 2

x = - 6 ± √36 + 36 / 2

x = - 6 ± √72 / 2

x = - 6 ± 8.48581374 / 2

- - - - - - - - -

Solving for +

x = - 6 + 8.485281374 / 2

x = 2.485281374 / 2

x = 1.242640687

- - - - - - - - - - - -

Solving for -

x = - 6 - 8.485281374 / 2

x = - 14.48528137 / 2

x = - 7.242640687

- - - - - - - - -s-

Answer 2

Solve by using the quadratic formula?
X to the second power plus 6x equals 9!
x^2+6x=91 or x^2+6x-91=0
using:
x=(1/2a)[-b+ or -sqrt(b^2-4ac)]
x=(1/2[-6+ or -sqrt(36+364)])=(1/2[-6+ or -20])=-13 or7 answer

Answer 3

x^2 + 6x = -9
x^2 + 6x + 9 = 0
a = 1
b = 6
c = 9

x = (-b +/- sqrt b^2 - 4ac)/2a

x =( -6 +/- sqrt 6^2 - 4(1)(9))/ 2(1)

x =( - 6 +/- sqrt 36 - 36)/2

x = (- 6 +/- 0)/2
x = -6/2
x = -3

To check:

x^2 + 6x = - 9
(-3)^2 + 6(-3) = - 9
9 - 18 = - 9
- 9 = - 9

Answer 4

rewrite:

x^2 + 6x + 9 = 0

a=1, b=6, c=9

using QF

x = [ -6 +- sqrt (36-36) ] / 2 = -3 (repeated twice)

Answer 5

x2+6x+9=0
x= (-b+ (b^2-4ac)^1/2)/2
x= (-6+ (6^2-4(1)(9)^1/2)/2
x= (-6+ (36-36)^1/2)/2
x= (-6+0)/2
x= -3

x^2 + 6x = -9
x^2 + 6x + 9 = 0
(x + 3)(x + 3) = 0
x = -3


i hope this helps you...

Answer 6

x = (-b +/- (b^2 -4ac)^.5) /2a

a =1 b=6 c=9

-6+ [(36-(4)(1)(9)]^.5 / 2
-6 - [(36-(4)(1)(9)]^.5 / 2

(-6 + 0) /2 = -3 (-6 - 0) /2 =-3
x = -3