Quadratics and Cubics, SMB-038 By completing the square, solve for `x` given `x^2+4x-1 = 0.` (3 marks) Show Answers Only `-2+-sqrt(5)` Show Worked Solution `x^2+4x-1` `=0` `x^2+4x+4-5` `=0` `(x+2)^2` `=5` `x+2` `= +-sqrt(5)` `x` `=-2+-sqrt(5)`