How do you solve d^2+5d+6=0d2+5d+6=0 using the quadratic formula?

1 Answer
Aug 10, 2015

The solutions for the equation are:
color(blue)(x=-2x=2

color(blue)(x=-3x=3

Explanation:

d^2+5d+6=0 d2+5d+6=0

The equation is of the form color(blue)(ad^2+bd+c=0ad2+bd+c=0 where:

a=1, b=5, c=6a=1,b=5,c=6

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

= (5)^2-(4*1*6)

= 25 - 24 = 1

As Delta=0 there is only one solution.

The solutions are found using the formula:

x=(-b+-sqrtDelta)/(2*a)

x = ((-5)+-sqrt(1))/(2*1) = (-5+-1)/2

The solutions for the equation are:
x =(-5+1)/2 , x=-4/2,color(blue)(x=-2

x =(-5-1)/2 , x=-6/2,color(blue)(x=-3