Answer to Question #162130 in Algebra for Chris

Question

Solve using the quadratic formula:

x² + 4x +3=0

Answer 1

x² + 4x +3=0

let's use the discriminant formula

D = b² - 4ac 

a=1

b=4

c=3

D = b² - 4ac = 4²-4*1*3=16-12=4

now let's find the x_{1 and} x₂ using the discriminant

x₁= $(-b+\sqrt{\smash[b]{D}})/2a$ = $(-4+\sqrt{\smash[b]{4}}))/2*1=(-4+2)/2=-2/2=-1$

x₂= $(-b-\sqrt{\smash[b]{D}})/2a$ =$(-4-\sqrt{\smash[b]{4}}))/2*1=(-4-2)/2=-6/2=-3$

The answer is

x₁= -1

x₂= -3