SOLUTION: Please show me how the basic form quadratic equation ax^2+bx+c=0 solves for x to become the quadratic formula: (-b+/-square root (b^2-4ac))/2a?

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Question 490458: Please show me how the basic form quadratic equation ax^2+bx+c=0 solves for x to become the quadratic formula: (-b+/-square root (b^2-4ac))/2a?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
done by completing the square

subtracting c ___ ax^2 + bx = -c

dividing by a ___ x^2 + (b/a)x = -c/a

adding half of the x-term coefficient, squared ___ x^2 + (b/a)x + (b/2a)^2 = (-c/a) + (b/2a)^2

x^2 + (b/a)x + (b/2a)^2 = (-c/a) + [(b^2)/(4a^2)] ___ x^2 + (b/a)x + (b/2a)^2 = [(-4ac)/(4a^2)] + [(b^2)/(4a^2)]

combining terms and taking sqrt ___ x + (b/2a) = ± [sqrt(b^2 - 4ac)] / 2a

subtracting (b/2a) and combining terms ___ x = {-b ± [sqrt(b^2 - 4ac)]} / 2a