document.write( "Question 1050747: This is a digit and coin word problem. I know how to do simpler digit and coin problems so the main thing I need help with is how to rewrite this as equations.
\n" ); document.write( "A two digit number is four times the sum of its digits. The ones digit is 4 more than the tens digit. Find the original number. \n" ); document.write( "
Algebra.Com's Answer #666357 by Edwin McCravy(20054)\"\" \"About 
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A two digit number is four times the sum of its digits.
\n" ); document.write( "The ones digit is 4 more than the tens digit.
\n" ); document.write( "Find the original number.
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document.write( "Every two-digit number is made up of the first digit,\r\n" );
document.write( "which tells us how many ten, and a ones (or units) digit,\r\n" );
document.write( "which tells how many ones.\r\n" );
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document.write( "For example, \r\n" );
document.write( "the two-digit number 64 has 6 tens and 4 ones and is 6(10)+4(1).\r\n" );
document.write( "the two-digit number 37 has 3 tens and 7 ones and is 3(10)+7(1).\r\n" );
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\n" ); document.write( "A two digit number is four times the sum of its digits.
\n" ); document.write( "The ones digit is 4 more than the tens digit.
\n" ); document.write( "Find the original number.
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document.write( "Let t = the tens digit\r\n" );
document.write( "Let u = the ones digit\r\n" );
document.write( "Then \r\n" );
document.write( "the number = 10t+u\r\n" );
document.write( "the sum of the digits = t+u\r\n" );
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\n" ); document.write( "A two digit number is four times the sum of its digits.
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document.write( "So 10t+u = 4(t+u)\r\n" );
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\n" ); document.write( "The ones digit is 4 more than the tens digit.
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document.write( "So u = t+4\r\n" );
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document.write( "We have this system of two equations and two unknowns:\r\n" );
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document.write( "\"system%2810t%2Bu=4%28t%2Bu%29%2Cu=t%2B4%29\"\r\n" );
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document.write( "Solve by substitution.  You finish.\r\n" );
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document.write( "Edwin
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