Answer:
x = -2 ± sqrt(5)
Step-by-step explanation:
x^2 + 4x – 1= 0
Add 1 to each side
x^2 + 4x – 1+1= 0+1
x^2 +4x = 1
Take the coefficient of x
4
Divide by 2
4/2 =2
Square it
2^2=4
Add it to each side
x^2 +4x+4=1+4
(x+2)^2 = 5
Take the square root of each side
sqrt((x+2)^2 )=± sqrt(5)
x+2 = ± sqrt(5)
Subtract 2 from each side
x+2-2 = -2 ± sqrt(5)
x = -2 ± sqrt(5)
