document.write( "Question 72517: Ricardo is 4 years less than twice as old as his sister. The sum of their ages is 20. How old is Ricardo? \n" ); document.write( "

Algebra.Com's Answer #51833 by jim_thompson5910(35256) $\"\"$ $\"About$

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Let r=ricardo's age, s=sister's age
\n" ); document.write( " $\"2s-4=r\"$ Here's their age relationship
\n" ); document.write( " $\"s%2Br=20\"$ Sum of their ages
\n" ); document.write( " $\"s=20-r\"$ Solve for s
\n" ); document.write( " $\"2%2820-r%29-4=r\"$ Plug in s=20-r
\n" ); document.write( " $\"40-2r-4=r\"$ solve for r
\n" ); document.write( " $\"36=3r\"$
\n" ); document.write( " $\"36%2F3=r\"$
\n" ); document.write( " $\"r=12\"$
\n" ); document.write( "So ricardo is 12 and his sister is:
\n" ); document.write( " $\"s=20-12\"$
\n" ); document.write( " $\"s=8\"$
\n" ); document.write( "Check:
\n" ); document.write( " $\"2%288%29-4=12\"$
\n" ); document.write( " $\"16-4=12\"$
\n" ); document.write( " $\"12=12\"$ Works \n" ); document.write( "

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