document.write( "Question 251591: Eight years ago, Ed was ten times as old as his youngest daughter Faith. In six years, he will only be three times as old as her. What are Ed's and Faith's ages now?\r
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\n" ); document.write( "\n" ); document.write( "10F-8=E-8
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\n" ); document.write( "\n" ); document.write( "They didn't work. I'm terrible with age problems. Please help! \n" ); document.write( "

Algebra.Com's Answer #789101 by ikleyn(52788) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "Let x be the daughter's age now, and let y be the Ed's age.\r\n" );
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document.write( "Eight years ago, the daughter was (x-8) years old;\r\n" );
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document.write( "                 Ed was (y-8) years old.\r\n" );
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document.write( "So, your first equation is\r\n" );
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document.write( "    y - 8 = 10*(x-8).     (1)\r\n" );
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document.write( "In six years, Ed will be (y+6) years old;\r\n" );
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document.write( "              his daughter will be (x+6) years old.\r\n" );
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document.write( "So, your second equation is\r\n" );
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document.write( "    y + 6 = 3*(x+6).        (2)\r\n" );
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document.write( "Now our task is to solve equations (1) and (2).\r\n" );
document.write( "For it, express y from equation (1)\r\n" );
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document.write( "    y = 10*(x-8) + 8 = 10x - 80 + 8 = 10x - 72     (3)\r\n" );
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document.write( "and substitute it into equation (2).  You will get\r\n" );
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document.write( "    10x - 72 + 6 = 3x + 18\r\n" );
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document.write( "    10x - 3x     = 18 + 72 - 6\r\n" );
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document.write( "    7x           = 84\r\n" );
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document.write( "     x           = 84/7 = 12.\r\n" );
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document.write( "Thus the daughter is 12 years old now.\r\n" );
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document.write( "Then the father is, according to (3), 10x - 72 = 10*12 - 72 = 120 - 72 = 48 years old.\r\n" );
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