document.write( "Question 617026: how do you use undoing with quadratic equation \n" ); document.write( "

Algebra.Com's Answer #388346 by KMST(5328) $\"\"$ $\"About$

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A generic quadratic equation would be $\"ax%5E2%2Bbx%2Bc=0\"$
\n" ); document.write( "We solve it by isolating the terms with x on one side of the equal sign and \"completing the square\".
\n" ); document.write( "Then we \"unsquare\" the completed square by taking square roots on both sides and adding the plus/minus options.
\n" ); document.write( "You can always do it in an equation with numbers coefficient,
\n" ); document.write( "but doing it with generic a, b, and c coefficients leads to the infamous quadratic formula.
\n" ); document.write( " $\"ax%5E2%2Bbx%2Bc=0\"$ --> $\"ax%5E2%2Bbx%2Bc-c=0-c\"$ --> $\"ax%5E2%2Bbx=-c\"$ --> $\"%28ax%5E2%2Bbx%29%2Fa=-c%2Fa\"$ --> $\"x%5E2%2B%28b%2Fa%29x=-c%2Fa\"$ --> $\"%28x%2B%28b%2Fa%29x%2B%28b%2F2a%29%5E2%29=%28b%5E2%2F4a%5E2%29-c%2Fa\"$
\n" ); document.write( "So $\"x%2Bb%2F2a=sqrt%28%28b%5E2-4ac%29%2F4a%5E2%29=sqrt%28b%5E2-4ac%29%2F2a\"$ or $\"x%2Bb%2F2a=sqrt%28%28b%5E2-4ac%29%2F4a%5E2%29=-sqrt%28b%5E2-4ac%29%2F2a\"$
\n" ); document.write( "In sum:
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