document.write( "Question 696813: Find (a, b, c) if
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document.write( "2a+3b+c=11
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document.write( "6ab+2ac+3bc=24
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document.write( "abc=-6 \n" );
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Algebra.Com's Answer #429459 by god2012(113)![]() ![]() You can put this solution on YOUR website! 2a+3b+c=11 ---------------------------------eq.1 \n" ); document.write( "6ab+2ac+3bc=24-------------------------------eq.2 \n" ); document.write( "abc=-6 -------------------------------------eq.3\r \n" ); document.write( "\n" ); document.write( "From Eq.1 , 2a+3b = 11 - c \n" ); document.write( "From eq.2 , 6ab + c (11 - c) = 24 \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "From eq.3 , ab = -6/c\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Therefore eq.4 becomes \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "By trial and error , one of the roots of the equation is -1. \n" ); document.write( "Therefore ,(c-1) is a factor. \n" ); document.write( "Let us reduce the cubic equation to a quadratic equation. \n" ); document.write( "We get , \n" ); document.write( "\n" ); document.write( "The roots are 6 and 6. \n" ); document.write( "c = {-1,6}\r \n" ); document.write( "\n" ); document.write( "Therefore 2a+3b = 11-(-1) = 12 --------------------eq.5 \n" ); document.write( "ab(-1) = -6 \n" ); document.write( "ab = 6 \n" ); document.write( "b = 6/a\r \n" ); document.write( "\n" ); document.write( "Substitute for b in eq.5\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Therefore , b = 2\r \n" ); document.write( "\n" ); document.write( "(a,b,c) = (3,2,-1) when c = -1 \n" ); document.write( "But when c = 6, we have 2 possibilities for a and b\r \n" ); document.write( "\n" ); document.write( "(a,b,c) = (3,-1/3,6) OR (-1/2 , 2,6)\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |