document.write( "Question 121030: Solve by using the quadratic formula: 4x^2-6x=9. Express roots in EXACT radical form if necessary. \n" ); document.write( "
Algebra.Com's Answer #88808 by solver91311(24713)\"\" \"About 
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To use the quadratic formula, the equation has to be in standard form, thus:\r
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\n" ); document.write( "\n" ); document.write( "\"ax%5E2%2Bbx%2Bc=0\"\r
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\n" ); document.write( "\n" ); document.write( "Your equation: \"4x%5E2-6x=9\" has to be re-arranged first.\r
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\n" ); document.write( "\n" ); document.write( "Add -9 to both sides:\r
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\n" ); document.write( "\n" ); document.write( "\"4x%5E2-6x-9=0\"\r
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\n" ); document.write( "\n" ); document.write( "Now we have a = 4, b = -6, and c = -9 and we can put these values into the quadratic formula:\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\" \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-6%29+%2B-+sqrt%28+%28-6%29%5E2-4%2A4%2A%28-9%29+%29%29%2F%282%2A4%29+\", and simplify
\n" ); document.write( "\"x+=+%286+%2B-+sqrt%28+36%2B144+%29%29%2F8+\"
\n" ); document.write( "\"x+=+%286+%2B-+sqrt%28+180+%29%29%2F8+\"\r
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\n" ); document.write( "\n" ); document.write( "160 = 2 * 2 * 3 * 3 * 5, so \"sqrt%28180%29=6%2Asqrt%285%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%286+%2B-+6%2Asqrt%28+5+%29%29%2F8+\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%283+%2B-+3%2Asqrt%28+5+%29%29%2F4+\"\r
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\n" ); document.write( "\n" ); document.write( "Therefore, \"x=%283%2B3sqrt%285%29%29%2F4\" or \"x=%283-3sqrt%285%29%29%2F4\"
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