document.write( "Question 169895: Please help show me how to work this problem out..Thank you...\r
\n" ); document.write( "\n" ); document.write( "solve equation using the quadratic formula\r
\n" ); document.write( "\n" ); document.write( "1/3x^2 + 2/9x - 1 = 0
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Algebra.Com's Answer #125321 by gonzo(654)\"\" \"About 
You can put this solution on YOUR website!
your equation is:
\n" ); document.write( "\"%281%2F3%29x%5E2+%2B+%282%2F9%29x+-+1+=+0\"
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\n" ); document.write( "quadratic formula is x = \"%28-b+%2B-+root%282%2Cb%5E2-4ac%29%29%2F%282a%29\"
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\n" ); document.write( "standard form of the quadratic equation is \"ax%5E2+%2B+bx+%2B+c+=+0\"
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\n" ); document.write( "you can make your calculations easier by multiplying each side of the equation by 9.
\n" ); document.write( "this will remove the denominators.
\n" ); document.write( "since the right side of the equation was 0, it will remain 0.
\n" ); document.write( "doing that, your formula becomes:
\n" ); document.write( "\"3x%5E2+%2B+2x+-+9+=+0\"
\n" ); document.write( "comparing to the standard form, you get
\n" ); document.write( "a = 3
\n" ); document.write( "b = 2
\n" ); document.write( "c = -9
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\n" ); document.write( "plugging these values into the quadratic formula, you get:
\n" ); document.write( "x = \"%28-%282%29+%2B-+root%282%2C%282%29%5E2-4%2A%283%29%2A%28-9%29%29%29%2F%282%2A%283%29%29\"
\n" ); document.write( "your answer is:
\n" ); document.write( "x = 1.430500874
\n" ); document.write( "or:
\n" ); document.write( "x = -2.097167541
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\n" ); document.write( "plugging these values into your original equations proves these values are good if the equation stays true.
\n" ); document.write( "it does.
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\n" ); document.write( "it is much easier to see if you have an equation that factors easily.
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\n" ); document.write( "take (x-1)*(x+2) = 0
\n" ); document.write( "these factors are chosen so that the resulting equation factors easier when using the quadratic equation to solve it.
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\n" ); document.write( "the resulting equation becomes x^2 +x-2=0
\n" ); document.write( "use the quadratic formula to solve this:
\n" ); document.write( "a = 1
\n" ); document.write( "b = 1
\n" ); document.write( "c = -2
\n" ); document.write( "quadratic formula of x = \"%28-b+%2B-+root%282%2Cb%5E2-4ac%29%29%2F%282a%29\"
\n" ); document.write( "becomes: x = \"%28-%281%29+%2B-+root%282%2C%281%29%5E2-4%2A%281%29%2A%28-2%29%29%29%2F%282%2A%281%29%29\"
\n" ); document.write( "this becomes: x = \"%28-%281%29+%2B-+root%282%2C9%29%29%2F%282%2A%281%29%29\"
\n" ); document.write( "which becomes: x = \"%28-%281%29+%2B-+3%29%2F%282%29\"
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\n" ); document.write( "x = (-1+3)/2 = 1
\n" ); document.write( "or:
\n" ); document.write( "x = (-1-3)/2 = -2
\n" ); document.write( "if x = 1, then (x-1) = 0
\n" ); document.write( "if x = -2, then (x+2) = 0
\n" ); document.write( "these are the factors you started with in creating this problem so the answers come out good.\r
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