document.write( "Question 620707: Solve: 73x is congruent to(the three line equal symbol) 115 (mod 971).\r
\n" );
document.write( "\n" );
document.write( "I know you can change this to (73x-115)/971, but I'm not sure how to solve the rest of this. \n" );
document.write( "
Algebra.Com's Answer #390349 by jim_thompson5910(35256)![]() ![]() ![]() You can put this solution on YOUR website! 73x = 1 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "971 | (73x - 1)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "971y = 73x - 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-73x + 971y = -1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73x - 971y = 1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "971 = 13*73 + 22 ----> 22 = 971 -13*73\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73 = 3*22 + 7 ----> 7 = 73 - 3*22\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "22 = 3*7 + 1 ----> 1 = 22 - 3*7\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 = 22 - 3*7\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 = 22 - 3*(73 - 3*22)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 = 22 - 3*73 + 9*22\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 = 971 -13*73 - 3*73 + 9*(971 - 13*73)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 = 971 - 13*73 - 3*73 + 9*971 - 117*73\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 = 10*971 - 13*73 - 3*73 - 117*73\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "1 = 10*971 - 133*73\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since 1 = 10*971 - 133*73, this means that for 73x = 1 (mod 971), the solution is x = -133 = 838 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73x = 1 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73*838 = 1 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now multiply both sides by 115\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73*838 = 1 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "115*73*838 = 115*1 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73*(115*838) = 115*1 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73*(115*838) = 115 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73*96370 = 115 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "73*241 = 115 (mod 971)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the solution for x in 73x = 115 (mod 971) is x = 241\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |