document.write( "Question 1088719: A father is four times as old as his son.In three years time the son will be twenty seven years younger than his father. What is their present ages?
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Algebra.Com's Answer #703024 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+a+\"$ = the father's age now
\n" ); document.write( "Let $\"+b+\"$ = the son's age now
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\n" ); document.write( "(1) $\"+a+=+4b+\"$
\n" ); document.write( "(2) $\"+%28+b+%2B+3+%29+=+%28+a+%2B+3+%29+-+27+\"$
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\n" ); document.write( "(2) $\"+b+%2B+3+=+a+-+24+\"$
\n" ); document.write( "(2) $\"+a+-+b+=+27+\"$
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\n" ); document.write( "Plug (1) into (2)
\n" ); document.write( "(2) $\"+4b+-+b+=+27+\"$
\n" ); document.write( "(2) $\"+3b+=+27+\"$
\n" ); document.write( "(2) $\"+b+=+9+\"$
\n" ); document.write( "and
\n" ); document.write( "(1) $\"+a+=+4b+\"$
\n" ); document.write( "(1) $\"+a+=+4%2A9+\"$
\n" ); document.write( "(1) $\"+a+=+36+\"$
\n" ); document.write( "The father is 36
\n" ); document.write( "The son is 9
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\n" ); document.write( "check:
\n" ); document.write( "(2) $\"+%28+b+%2B+3+%29+=+%28+a+%2B+3+%29+-+27+\"$
\n" ); document.write( "(2) $\"+%28+9+%2B+3+%29+=+%28+36+%2B+3+%29+-+27+\"$
\n" ); document.write( "(2) $\"+12+=+39+-+27+\"$
\n" ); document.write( "(2) $\"+12+=+12+\"$
\n" ); document.write( "OK
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