Question

Solve x2 + 4x + 12 = 0 by completing the square.

x = –2 + 2i, x = –2 –2i

x = –2 + i, x = –2 – i

x = –2 + 2i, x = –2 – 2i

x = 0, –4

Answer 1

See below

Explanation:

x2 + 4x + 12 = 0 Complete the square ( take 1/2 of the 'x' coefficient, then square it and add it to both sides of the equation

x^2 + 4x + 2^2 + 12 = 2^2 Subtract 12 from both sides

x^2 + 4x + 4 = -8

(x+2)^2 = - 8 sqrt both sides

(x+2) =± sqrt (-8) simplify just a bit

x+2 = ±(2i sqrt2) subtract 2 from both sides

x = -2 ± 2i sqrt 2 <===== I do not see that answer listed