quadratic formula.??????

Question

Find the roots of the equation by using the quadratic formula. x^2 +8x+12 =0

how do you do this? show work plz

Answer 1

Comparing the equation with standard quadratic equation ax^2+bx+c=0,we get
a=1,b=8 and c=12
we know that x={-b+-sqrt(b^2-4ac)}/2a
Therefore,
x={-8+-sqrt(64-48)}/2
=(-8+-4)/2
= -12/2 or -4/2
= -6 or -2

Answer 2

For equation ax² + bx + c = 0 ,the solution is given by:-
x = [- b ± √(b² - 4ac) ] / 2a
In given question, a = 1 , b = 8 and c = 12
x = [ - 8 ± √(8² - 48) ] / 2
x = [- 8 ± √16 ] / 2
x = - 4/2 , x = - 12/2
x = - 2 , x = - 6
May also use factors as a check:-
x² + 8x + 12 = 0
(x + 6).(x + 2) = 0
x = - 6 , x = - 2 (as above)

Answer 3

x^2+8x+12=0
x^2+6x+2x+12=0
x(x+6) + 2(x+6) =0
(x+2) (x+6)=0
x= -2,-6

Answer 4

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

a = 1 b = 8 c = 12

x = [-8 +- sqrt(64 - 4*1*12)] / 2
x = [-8 +- sqrt(16)] / 2
x = (-8 +- 4) / 2
x = -4/2 = -2
x = -12/2 = -6

Also could be done by factoring: (x+2)(x+6) = 0