X to the 2nd power plus 2x equals 12?

Answer 1

x2+ 2x = 12 (complete the square)

x^2 + 2x + 1 = 12 + 1 (x + 1)^2 = 13 (square root of both sides) x + 1 = ±√13 (subtract 1 to both sides) x = ±√13 - 1 x = √13 - 1 or x = -√13 - 1 x= 2.6 or -4.6