document.write( "Question 182933: Please I need help with: quintun was solving a quadestic equation in the form ax^2+bx+c=0 using the quadestic formula. He made the mistake, however, of switching a and c in the formula and and as a result he got answers that were 3 times the correct answer. Find the product of the roots of the quadratic equation \n" ); document.write( "
Algebra.Com's Answer #137373 by Edwin McCravy(20054)\"\" \"About 
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Please I need help with: quintun was solving a quadestic equation in the form ax^2+bx+c=0 using the quadestic formula. He made the mistake, however, of switching a and c in the formula and and as a result he got answers that were 3 times the correct answer. Find the product of the roots of the quadratic equation.
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document.write( "For any quadratic equation of the form\r\n" );
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document.write( "\"+matrix%281%2C7%2Cax%5E2%2C%22%2B%22%2Cbx%2C%22%2B%22%2Cc%2C%22=%22%2C0%29\",\r\n" );
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document.write( "the product of the two roots is \"c%2Fa\".\r\n" );
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document.write( "Suppose the two roots are \"p\" and \"q\"\r\n" );
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document.write( "Then \"matrix%281%2C3%2Cpq%2C+%22=%22%2C+c%2Fa%29\"\r\n" );
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document.write( "When he switched \"a\" and \"c\" in the\r\n" );
document.write( "quadratic formula, he got the roots for\r\n" );
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document.write( "\"+matrix%281%2C7%2Ccx%5E2%2C%22%2B%22%2Cbx%2C%22%2B%22%2Ca%2C%22=%22%2C0%29\",\r\n" );
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document.write( "to be \"3p\" and \"3q\"\r\n" );
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document.write( "So their product \"%283p%29%283q%29\" is \"9pq\",\r\n" );
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document.write( "and that had to equal the number \"a%2Fc\"\r\n" );
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document.write( "so \"9pq=a%2Fc\"\r\n" );
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document.write( "So we have the system:\r\n" );
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document.write( "\"system%28pq=c%2Fa%2C9pq=a%2Fc%29\"\r\n" );
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document.write( "Clearing of fractions:\r\n" );
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document.write( "\"system%28apq=c%2C9cpq=a%29\"\r\n" );
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document.write( "Solving each for the product \"pq\"\r\n" );
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document.write( "\"system%28pq=c%2Fa%2Cpq=a%2F%289c%29%29\"\r\n" );
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document.write( "So we have\r\n" );
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document.write( "\"c%2Fa=a%2F%289c%29\"\r\n" );
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document.write( "cross-multiplying gives:\r\n" );
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document.write( "\"9c%5E2=a%5E2\"\r\n" );
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document.write( "or\r\n" );
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document.write( "\"9c%5E2-a%5E2=0\"\r\n" );
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document.write( "so, factoring,\r\n" );
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document.write( "\"%283c-a%29%283c%2Ba%29=0\"\r\n" );
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document.write( "So either \"3c=a\" or \"-3c=a\"\r\n" );
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document.write( "Now in the first case, substitution of\r\n" );
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document.write( "of \"3c\" for \"a\" in \r\n" );
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document.write( "\"matrix%281%2C3%2Cpq%2C+%22=%22%2C+c%2Fa%29\"\r\n" );
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document.write( "gives\r\n" );
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document.write( "\"matrix%281%2C3%2Cpq%2C+%22=%22%2C+c%2F%283c%29%29\"\r\n" );
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document.write( "\"matrix%281%2C3%2Cpq%2C+%22=%22%2C+1%2F3%29\"\r\n" );
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document.write( "---\r\n" );
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document.write( "In the second case, substitution of\r\n" );
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document.write( "of \"-3c\" for \"a\" in \r\n" );
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document.write( "\"matrix%281%2C3%2Cpq%2C+%22=%22%2C+c%2Fa%29\"\r\n" );
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document.write( "gives\r\n" );
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document.write( "\"matrix%281%2C3%2Cpq%2C+%22=%22%2C+c%2F%28-3c%29%29\"\r\n" );
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document.write( "\"matrix%281%2C3%2Cpq%2C+%22=%22%2C+-1%2F3%29\"\r\n" );
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document.write( "So the product of the roots is either\r\n" );
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document.write( "\"1%2F3\" or \"-1%2F3\"\r\n" );
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document.write( "Those are the answers!\r\n" );
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document.write( "----------------------------------------\r\n" );
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document.write( "If you want to demonstrate those answers in\r\n" );
document.write( "specific cases, solve the quadratic equation:\r\n" );
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document.write( "\"6x%5E2-7x%2B2=0\" and you'll find the solutions\r\n" );
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document.write( "and \"2%2F3\" and \"1%2F2\" which have \r\n" );
document.write( "product \"1%2F3\"\r\n" );
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document.write( "Then switch \"a\" and \"c\" and you'll\r\n" );
document.write( "get the equation\r\n" );
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document.write( "\"2x%5E2-7x%2B6=0\" and you'll find that it has\r\n" );
document.write( "solutions  \"2\" and \"3%2F2\" which \r\n" );
document.write( "are 3 times the solutions \"2%2F3\" and \"1%2F2\".\r\n" );
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document.write( "Edwin
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