Then use the completing the square method.Originally Posted bydigideens

x^2 -4x -6 = 0

x^2 -4x = 6

x^2 -4x +(-4/2)^2 = 6 +(-4/2)^2

x^2 -4x +4 = 6 +4

(x-2)^2 = 10

Take the square roots of both sises,

x-2 = +,-sqrt(10)

So,

x = 2 +sqrt(10)

or,

x = 2 -sqrt(10)