document.write( "Question 1188489: Peter is forty years old and his son is ten years old. How long will it take so that will Peter be twice as old as his son? \n" ); document.write( "

Algebra.Com's Answer #819577 by ikleyn(52803) $\"\"$ $\"About$

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document.write( "Let x be the number of years to pass.\r\n" );
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document.write( "Then your basic equation is this\r\n" );
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document.write( "    40 + x = 2*(10+x)\r\n" );
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document.write( "Simplify and find x\r\n" );
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document.write( "    40 + x = 20 + 2x\r\n" );
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document.write( "    40 - 20 = 2x - x\r\n" );
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document.write( "      20    =    x\r\n" );
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document.write( "ANSWER.  In 20 years.\r\n" );
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document.write( "CHECK.  In 20 years their ages will be  10+20 = 30 (the son)  and  40 + 20 = 60  (the father).\r\n" );
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