document.write( "Question 24225: The combined age of two people is 91. Person A is twice as old as person
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Algebra.Com's Answer #12880 by AnlytcPhil(1806)\"\" \"About 
You can put this solution on YOUR website!
The combined age of two people is 91. Person A is twice as old as person\r\n" );
document.write( "B was when Person A was as old as Person B is now. How old is each person?\r\n" );
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document.write( ">>...The combined age of two people is 91...<<\r\n" );
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document.write( "Translation into algebra:  A + B = 91\r\n" );
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document.write( ">>...Person A is twice as old as person B was when Person A was as old as\r\n" );
document.write( "Person B is now...<<\r\n" );
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document.write( "Do a little bit of rewording in terms of \"X years ago\", and make\r\n" );
document.write( "these two new sentences from it:\r\n" );
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document.write( ">>...Person A is twice as old as person B was X years ago...<<\r\n" );
document.write( ">>...X years ago was when Person A was as old as Person B is now...<<\r\n" );
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document.write( "Taking the first new sentence:\r\n" );
document.write( " >>...Person A is twice as old as person B was X years ago...<<\r\n" );
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document.write( "X years ago, B wsa B-X, so\r\n" );
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document.write( "A = 2(B-X)\r\n" );
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document.write( "Taking the second :\r\n" );
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document.write( ">>...X years ago Person A was as old as Person B is now...<<\r\n" );
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document.write( "X years ago, A was A-X.  So \r\n" );
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document.write( "A-X = B\r\n" );
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document.write( "So we have three equations and 3 unknowns:\r\n" );
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document.write( "A + B = 91\r\n" );
document.write( "A = 2(B-X)\r\n" );
document.write( "A-X = B\r\n" );
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document.write( "Can you solve that system of equations?  If not post again.\r\n" );
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document.write( "Answer: A = 52, B = 39, X = 13\r\n" );
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document.write( "Checking:\r\n" );
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document.write( "Their combined age is 91.  52+39 = 91.  That checks\r\n" );
document.write( ">>...Person A is twice as old as person B was X years ago...<<\r\n" );
document.write( "13 years ago B was 39-13 or 26, and A is 52 which is twice that.\r\n" );
document.write( "That checks.\r\n" );
document.write( ">>...X years ago Person A was as old as Person B is now...<<\r\n" );
document.write( "13 years ago Person A was 52-13 or 39, and that's how old Person B\r\n" );
document.write( "is now, so that checks.\r\n" );
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document.write( "Edwin\r\n" );
document.write( "AnlytcPhil@aol.com
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