document.write( "Question 68859: The value of a certain 2 digit number is 5 times the sum of its digits. If the digits are reversed,the resulting number 9 more than the original number . Find the original number. T is supposed to represent the tens, and U is supposed to represent the unit. Help. Need to write out this equation and solve it. Spent 3 hours already!! \n" ); document.write( "
Algebra.Com's Answer #49009 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! The value of a certain 2 digit number is 5 times the sum of its digits. If the digits are reversed,the resulting number 9 more than the original number . Find the original number. T is supposed to represent the tens, and U is supposed to represent the unit. \n" ); document.write( "--------- \n" ); document.write( "Value = 10T+U (Just like 32 = 10(3)+2) \n" ); document.write( "5 times sum of its digits = 5(T+U) \n" ); document.write( "If digits are reversed Value = 10U+T \n" ); document.write( "---------------- \n" ); document.write( "EQUATIONS: \n" ); document.write( "1st: 10T+U=5(T+U) \n" ); document.write( "2nd: 10U+T = 10T+U+9 \n" ); document.write( "--------------- \n" ); document.write( "Rewrite the equations: \n" ); document.write( "1st becomes: 5T-4U=0 \n" ); document.write( "2nd becomes: 9T-9U+9=0 \n" ); document.write( "2nd again: T-U=-1 \n" ); document.write( "----------------- \n" ); document.write( "Rewriting the two equations: \n" ); document.write( "1st: 5T-4U=0 \n" ); document.write( "2nd:T-U=-1 \n" ); document.write( "Solve 2nd for T to get: \n" ); document.write( "3rd: T=U-1 \n" ); document.write( "Substitute into 1st to get: \n" ); document.write( "5(U-1)-4U=0 \n" ); document.write( "U=1 \n" ); document.write( "Substitute that into 3rd to get: \n" ); document.write( "T=1-1=0 \n" ); document.write( "--------- \n" ); document.write( "The two digit number is 01 \n" ); document.write( "When you reverse it you get 10 which is 9 more than the original. \n" ); document.write( "--------- \n" ); document.write( "Cheers, \n" ); document.write( "Stan H.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |