Question 252957
Besides the quadratic formula we can complete the square
x^2+6x-3=0
x^2+6x=3
take half of 6 
6/2=3
and square it
3^2=9
add 9 to both sides
x^2+6x+9=12
(x+3)^2=12
x+3=+\-sqrt(12)
x=-3+sqrt(12)
x=-3-sqrt(12)

x=-3+2sqrt(3)
x=-3-2sqrt(3)