document.write( "Question 1035686: Sara's age is 7 more than antonio's age.Two times Antonio's age plus 3 times sara's age is equal to 36. How old are they? \n" ); document.write( "

Algebra.Com's Answer #650349 by ikleyn(52788) $\"\"$ $\"About$

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\n" ); document.write( "Sara's age is 7 more than antonio's age.Two times Antonio's age plus 3 times sara's age is equal to 36. How old are they?
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document.write( "s = a + 7,      (1)\r\n" );
document.write( "2a + 3s = 36.   (2)\r\n" );
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document.write( "Substitute expression (1) for s into (2). You will get a single equation for a:\r\n" );
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document.write( "2a + 3*(a+7) = 36,\r\n" );
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document.write( "2a + 3a + 21 = 36,\r\n" );
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document.write( "5a = 36 - 21 = 15,\r\n" );
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document.write( "a = 3.\r\n" );
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document.write( "Antonio is 3 years old.\r\n" );
document.write( "Sara's age is 3 + 7 = 10 years.\r\n" );
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