document.write( "Question 147026: MArcos is 7 years older than his sister, Rosa. The sum of their ages is 1 less than 3 tomes Rosa's age. How old is each? \n" ); document.write( "
Algebra.Com's Answer #107359 by ankor@dixie-net.com(22740)\"\" \"About 
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Write an equation for each statement:
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\n" ); document.write( "MArcos is 7 years older than his sister, Rosa.
\n" ); document.write( "M = R + 7
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\n" ); document.write( "The sum of their ages is 1 less than 3 times Rosa's age.
\n" ); document.write( "M + R = 3R - 1
\n" ); document.write( "M = 3R - R - 1
\n" ); document.write( "M = 2R - 1
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\n" ); document.write( "How old is each?
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\n" ); document.write( "Substitute (R+7) for M in the above equation
\n" ); document.write( "R + 7 = 2R - 1
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\n" ); document.write( "7 + 1 = 2R - R
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\n" ); document.write( "R = 8 yrs is Rosa's age
\n" ); document.write( "then
\n" ); document.write( "M = 2(8) - 1 = 15 yrs is Marc's age
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\n" ); document.write( "Check solution in the statement
\n" ); document.write( "The sum of their ages is 1 less than 3 times Rosa's age.
\n" ); document.write( "15 + 8 = 3(8) - 1 \n" ); document.write( "
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