x^2 - 4x + 12 = 0

Question

I need the square to be completed... please.

Answer 1

The equation x ² - 4x + 12 = 0

Separate variables and constants aside by subtracting 12 from each side.

x² - 4x  = - 12

 To change the expression into a perfect square trinomial add (half the x coefficient)² to each side of the expression

 Here x coefficient = - 4. so, (half the x coefficient)² = (- 4/2)²= 4

Add 4 to each side

x² - 4x + 4 = - 12 + 4

(x  - 2)²= - 8

Take square root both sides

x - 2 = ± √-8

x = 2 ± 2.82i

solutions are x = 2 + 2.82i and x = 2 - 2.82i.