document.write( "Question 1204754: Martin asked his grandfather how old he was, he replied “my age is 4 times your age, but 5 years ago it was 5 times yours.” How old is his grandfather? \n" ); document.write( "

Algebra.Com's Answer #841218 by ikleyn(52788) $\"\"$ $\"About$

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\n" ); document.write( "Martin asked his grandfather how old he was, he replied “my age is 4 times your age, but 5 years ago it was 5 times yours.” How old is his grandfather?
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document.write( "Let x be the Martin's age.\r\n" );
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document.write( "Then the grandfather's current age is  4x, according to the problem.\r\n" );
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document.write( "5 years ago\r\n" );
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document.write( "    5(x-5) = 4x-5.     (5 years ago the grandfather's age was 5 times Martin's age)\r\n" );
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document.write( "Simplify and find x\r\n" );
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document.write( "    5x - 25 = 4x - 5\r\n" );
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document.write( "    5x - 4x = 25 - 5\r\n" );
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document.write( "       x    =   20.\r\n" );
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document.write( "ANSWER.  Grandfather is 4*20 = 80 years old.\r\n" );
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\n" ); document.write( "\n" ); document.write( "You may check it on your own that my answer satisfies all problem descriptions.\r
\n" ); document.write( "\n" ); document.write( "(I did it mentally for myself. Checking is an integral part of any solution, as you know or should know).\r
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