document.write( "Question 534835: y =2x^2-12x-20 Is The Equation, And I Don't Understand How To Find The Answer \n" ); document.write( "
Algebra.Com's Answer #351661 by fcabanski(1391)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "The goal is to find the roots of the equation. That is, the value of x when y=0:


\n" ); document.write( "0 = 2x^2-12x-20 (the first thing we can do is factor out 2.)

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\n" ); document.write( "\n" ); document.write( "0=x^2-6x-10 (We cannot easily factor this with reverse foil, so we need to use the quadratic equation (-b + or - sqrt (b^2-4ac))/2a:


\n" ); document.write( "a=1, b=-6, c=-10.

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\n" ); document.write( "\n" ); document.write( "(-(-6) + or - sqrt (-6^2 - 4(1)(-10)))/2(1)=


\n" ); document.write( "(6 + or - sqrt (36+40))/2 =


\n" ); document.write( "(6 + or - sqrt(76))/2 =


\n" ); document.write( "(6 + or - sqrt(4*19))/2 =


\n" ); document.write( "(6 + or - 2sqrt(19))/2 =


\n" ); document.write( "3 + or - sqrt(19) \n" ); document.write( "

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