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!
Answer this Question
Related Questions
Algebra  My homework is to solve by completing the square. But how can you ...
Algebra  Complete the square for the binomial. Then factor the resulting ...
Algebra  Complete the square for the binomial. Then factor the resulting ...
Algebra I  The distance an object falls is directly propotional to the square ...
algebra  solve the polynomial y=2x^24x+1 For Further Reading algebra  Reiny, ...
algrebra 2  it is called completing the square here is the equation 4x^24x+1=9...
math,help,algebra I  I need help can someone help me get unstuck and let me ...
Pre Cal  Ooops! I wrote it wrong, here's the problem: if x varies directly as y...
Math  She wants us to complete the square for this problem, but I cannot get it...
Algebra Word problem  I don't know how to put in a square root symbol here so ...