document.write( "Question 1113756: David and Alex have a total of 25 years. John is 10 years older than David. How old is Alex if 5 year from now, John will be 16 years old? \n" ); document.write( "

Algebra.Com's Answer #728846 by Edwin McCravy(20065) $\"\"$ $\"About$

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David and Alex have a total of 25 years.
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document.write( "(1)     D + A = 25\r\n" );
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\n" ); document.write( "John is 10 years older than David.
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document.write( "(2)     J = D + 10\r\n" );
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\n" ); document.write( "5 years from now, John will be 16 years old.
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document.write( "(3)     J + 5 = 16\r\n" );
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\n" ); document.write( "How old is Alex?
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document.write( "Solve (3)\r\n" );
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document.write( "       J + 5 = 16\r\n" );
document.write( "           J = 11\r\n" );
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document.write( "Substitute 11 for J in (2)\r\n" );
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document.write( "       J = D + 10\r\n" );
document.write( "      11 = D + 10\r\n" );
document.write( "       1 = D\r\n" );
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document.write( "Substitute 1 for D in (1)\r\n" );
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document.write( "       D + A = 25\r\n" );
document.write( "       1 + A = 25\r\n" );
document.write( "           A = 24\r\n" );
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document.write( "Alex is 24.\r\n" );
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document.write( "Checking:  A = 24, D = 1, J = 11 \r\n" );
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\n" ); document.write( "David and Alex have a total of 25 years.
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document.write( "That checks because 1 + 24 = 25\r\n" );
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\n" ); document.write( "John is 10 years older than David.
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document.write( "That checks because 11 = 1 + 10\r\n" );
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\n" ); document.write( "How old is Alex if 5 year from now, John will be 16 years old?
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document.write( "That checks because 11 + 5 = 16.\r\n" );
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document.write( "Edwin

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