SOLUTION: how do you use undoing with quadratic equation

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Question 617026: how do you use undoing with quadratic equation
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
A generic quadratic equation would be ax%5E2%2Bbx%2Bc=0
We solve it by isolating the terms with x on one side of the equal sign and "completing the square".
Then we "unsquare" the completed square by taking square roots on both sides and adding the plus/minus options.
You can always do it in an equation with numbers coefficient,
but doing it with generic a, b, and c coefficients leads to the infamous quadratic formula.
ax%5E2%2Bbx%2Bc=0 --> ax%5E2%2Bbx%2Bc-c=0-c --> ax%5E2%2Bbx=-c --> %28ax%5E2%2Bbx%29%2Fa=-c%2Fa --> x%5E2%2B%28b%2Fa%29x=-c%2Fa --> %28x%2B%28b%2Fa%29x%2B%28b%2F2a%29%5E2%29=%28b%5E2%2F4a%5E2%29-c%2Fa
So x%2Bb%2F2a=sqrt%28%28b%5E2-4ac%29%2F4a%5E2%29=sqrt%28b%5E2-4ac%29%2F2a or x%2Bb%2F2a=sqrt%28%28b%5E2-4ac%29%2F4a%5E2%29=-sqrt%28b%5E2-4ac%29%2F2a
In sum: