document.write( "Question 195565: Please help me solve this: 15x^2-7x-4=0 \n" ); document.write( "
Algebra.Com's Answer #146668 by jim_thompson5910(35256)\"\" \"About 
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\"15x%5E2-7x-4=0\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic equation in the form of \"ax%5E2%2Bbx%2Bc\" where \"a=15\", \"b=-7\", and \"c=-4\"\r
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\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%28-7%29+%2B-+sqrt%28+%28-7%29%5E2-4%2815%29%28-4%29+%29%29%2F%282%2815%29%29\" Plug in \"a=15\", \"b=-7\", and \"c=-4\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+%28-7%29%5E2-4%2815%29%28-4%29+%29%29%2F%282%2815%29%29\" Negate \"-7\" to get \"7\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+49-4%2815%29%28-4%29+%29%29%2F%282%2815%29%29\" Square \"-7\" to get \"49\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+49--240+%29%29%2F%282%2815%29%29\" Multiply \"4%2815%29%28-4%29\" to get \"-240\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+49%2B240+%29%29%2F%282%2815%29%29\" Rewrite \"sqrt%2849--240%29\" as \"sqrt%2849%2B240%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+289+%29%29%2F%282%2815%29%29\" Add \"49\" to \"240\" to get \"289\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+289+%29%29%2F%2830%29\" Multiply \"2\" and \"15\" to get \"30\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+17%29%2F%2830%29\" Take the square root of \"289\" to get \"17\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B+17%29%2F%2830%29\" or \"x+=+%287+-+17%29%2F%2830%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2824%29%2F%2830%29\" or \"x+=++%28-10%29%2F%2830%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+4%2F5\" or \"x+=+-1%2F3\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+4%2F5\" or \"x+=+-1%2F3\"
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