Use the Quadratic formula,
x= -b +/- sqrt(b^2-4ac)
-------------------------
2a
x= 4 +/- sqrt(16+12)
----------------------
-6
x = 4+/- sqrt(28)
---------------
-6
x = 4 +/- 2*sqrt(7)
------------------
-6
x= 2(2+/- sqrt(7))
------------------
2(-3)
x= 2+/- sqrt(7)
--------------
-3
