document.write( "Question 391708: If x is 2,3,4 and Y is 11,49,123 what is the rule? \r
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Algebra.Com's Answer #277889 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Try a quadratic equation  y = ax²+ bx + c\r\n" );
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document.write( "Substitute x = 2 and y = 11\r\n" );
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document.write( "  y = ax²+ bx + c\r\n" );
document.write( " 11 = a(2)²+ b(2) + c\r\n" );
document.write( " 49 = a(3)²+ b(3) + c\r\n" );
document.write( "123 = a(4)²+ b(4) + c\r\n" );
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document.write( "Simplify:\r\n" );
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document.write( " 11 =  4a + 2b + c\r\n" );
document.write( " 49 =  9a + 3b + c\r\n" );
document.write( "123 = 16a + 4b + c\r\n" );
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document.write( "Solve that system of equations and get\r\n" );
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document.write( "a = 18, b = -52, c = 43\r\n" );
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document.write( "So an equation that fits the given data is:\r\n" );
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document.write( " y = ax²+ bx + c\r\n" );
document.write( " y = 18x²- 52x + 43\r\n" );
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document.write( "Edwin
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