document.write( "Question 1195856: If 321n=232seven find n\r
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Algebra.Com's Answer #828439 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "The problem is this: \n" ); document.write( "321 (base n) = 232 (base 7) \n" ); document.write( "Informally.... \n" ); document.write( "In any base (where the numbers are defined), 321 is greater than 232; so if 321 (base n) is equal to 232 (base 7), then the base n must be less than 7. \n" ); document.write( "So try n=6.... \n" ); document.write( "321 (base 6) \n" ); document.write( "3*6=18; 18+2=20 \n" ); document.write( "20*6=120; 120+1=121 \n" ); document.write( "232 (base 7) \n" ); document.write( "2*7=14; 14+3=17 \n" ); document.write( "17*7=119; 119+2=121 \n" ); document.write( "n=6 works! \n" ); document.write( "ANSWER: n=6 \n" ); document.write( "Formally.... \n" ); document.write( "321 (base n) = 3n^2+2n+1 \n" ); document.write( "232 (base 7) = 2(7^2)+3(7)+2 = 98+21+2 = 121 \n" ); document.write( "3n^2+2n+1=121 \n" ); document.write( "3n^2+2n-120 = 0 \n" ); document.write( "(n-6)(3n+20) = 0 \n" ); document.write( "n=6 or n=-20/3 \n" ); document.write( "Obviously the negative fractional answer makes not sense. So \n" ); document.write( "ANSWER: n=6 \n" ); document.write( " \n" ); document.write( " |