document.write( "Question 310882: Next year Peter will be twice as old as his sister will be. She is three years younger than he. How old is each one now? \n" ); document.write( "

Algebra.Com's Answer #222436 by Fombitz(32388) $\"\"$ $\"About$

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$\"P\"$ -Peter's age right now
\n" ); document.write( " $\"S\"$ -Sister's age right now
\n" ); document.write( "Next year, Peter will be $\"P%2B1\"$ , Sister will be $\"S%2B1\"$ .
\n" ); document.write( "1. $\"P%2B1=2%28S%2B1%29\"$
\n" ); document.write( "2. $\"S=P-3\"$
\n" ); document.write( "Substitute eq. 2 into eq. 1,
\n" ); document.write( " $\"P%2B1=2%28P-3%2B1%29\"$
\n" ); document.write( " $\"P%2B1=2%28P-2%29\"$
\n" ); document.write( " $\"P%2B1=2P-4\"$
\n" ); document.write( " $\"-P=-5\"$
\n" ); document.write( " $\"highlight%28P=5%29\"$
\n" ); document.write( "Then from eq. 2,
\n" ); document.write( " $\"S=P-3=5-3\"$
\n" ); document.write( " $\"highlight_green%28S=2%29\"$
\n" ); document.write( "Peter is 5 years old, his sister is 2 years old.
\n" ); document.write( " \n" ); document.write( "

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