Make x the subject of the equation

y = x^2 +2x -1

y = x^2 + 2x - 1
y + 1 = x^2 + 2x + 1 - 1
y + 1 = (x + 1)^2 - 1
y + 2 = (x + 1)^2
(y + 2)^(1/2) = x + 1
(y + 2)^(1/2) - 1 = x

y+1=x^2 + 2x
y+1+1=x^2+2x+1
y+2=(x+1)^2
x=(y+2)^.5-1 , -(y+2)^.5-1
:)