document.write( "Question 1035216: Two years ago john was 7 times as old as his son but in 3 years he wil be 4 times as old as the boy. How old is john? \n" ); document.write( "

Algebra.Com's Answer #649858 by rothauserc(4718) $\"\"$ $\"About$

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Let x be the age of John and y be the age of his son
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\n" ); document.write( "1) x-2 = 7 * (y-2)
\n" ); document.write( "2) x+3 = 4 * (y+3)
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\n" ); document.write( "Use equation 1 and solve for x
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\n" ); document.write( "x-2 = 7y-14
\n" ); document.write( "x = 7y-12
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\n" ); document.write( "Substitute for x in equation 2
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\n" ); document.write( "7y-12+3 = 4y+12
\n" ); document.write( "3y = 21
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\n" ); document.write( "y = 7
\n" ); document.write( "x = 49-12 = 37
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\n" ); document.write( "John is 37 years old
\n" ); document.write( "John's son is 7 years old
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