document.write( "Question 307202: If three times the square of a negative number is added to the product of -7 and the number the result is 20. Find the number. \n" ); document.write( "
Algebra.Com's Answer #219792 by jim_thompson5910(35256)\"\" \"About 
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The phrase \"three times the square of a negative number is added to the product of -7 and the number the result is 20.\" translates to \"3x%5E2-7x=20\" where 'x' is a negative number.\r
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\n" ); document.write( "\n" ); document.write( "\"3x%5E2-7x=20\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"3x%5E2-7x-20=0\" Subtract 20 from both sides.\r
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\n" ); document.write( "\n" ); document.write( "Notice that the quadratic \"3x%5E2-7x-20\" is in the form of \"Ax%5E2%2BBx%2BC\" where \"A=3\", \"B=-7\", and \"C=-20\"\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%283%29%28-20%29+%29%29%2F%282%283%29%29\" Plug in \"A=3\", \"B=-7\", and \"C=-20\"\r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+sqrt%28+%28-7%29%5E2-4%283%29%28-20%29+%29%29%2F%282%283%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%283%29%28-20%29+%29%29%2F%282%283%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%283%29%29\" Multiply \"4%283%29%28-20%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%283%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%283%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%286%29\" Multiply \"2\" and \"3\" to get \"6\". \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%287+%2B-+17%29%2F%286%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%286%29\" or \"x+=+%287+-+17%29%2F%286%29\" Break up the expression. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+%2824%29%2F%286%29\" or \"x+=++%28-10%29%2F%286%29\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "\"x+=+4\" or \"x+=+-5%2F3\" Simplify. \r
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\n" ); document.write( "\n" ); document.write( "So the possible solutions are \"x+=+4\" or \"x+=+-5%2F3\" \r
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\n" ); document.write( "\n" ); document.write( "Keep in mind that 'x' is a negative number. So the only answer is \"x+=+-5%2F3\"\r
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