+33665 Write it as
2(x^2 - 4x - 11) = 0 Divide by 2
x^2 - 4x - 11 = 0 Add 4 to both sides (the square of half of the coefficient of x).
x^2 - 4x + 4 - 11 = 4 Add 11 to both sides
x^2 - 4x + 4 = 15 The left=hand side can now be written as a square:
(x - 2)^2 = 15 Take square root of both sides
\(x-2=\pm \sqrt{15}\) Add 2 to both sides
\(x =2\pm \sqrt{15}\)
