Posted by Christina on Wednesday, January 5, 2011 at 10:07pm.
x^2  4x = 12
x^2  4x + 4 = 12 + 4
(x2)^2 = 8
x2 = ± √8 , but √8 = 2√2 √1 = 2i√2
x = 2 ± 2i√2
Easist way always is to go and get the roots:
(b + sqrt(b^2  4ac)) / 2a

x^2 4x +12 = 0
a= 1, b=4 c = 12
((4) + sqrt(16  4*12)) / 2

(4 + sqrt(32))/2

4 + sqrt(i^2 * 16 *2))/2

note : i^2 = 1
(4 + i 4 sqrt(2))/2

Ans:
2+ 2i sqrt(2)

are the two roots
Hope this helps Christine!
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