document.write( "Question 501422: the sum of ages of dina and cora is 30. three yers ago cora was three times as old as dina. What are their present age? \n" ); document.write( "

Algebra.Com's Answer #338523 by oberobic(2304) $\"\"$ $\"About$

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d = Dina's age
\n" ); document.write( "c = Cora's age
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\n" ); document.write( "d+c = 30
\n" ); document.write( "so
\n" ); document.write( "d = 30-c
\n" ); document.write( "c = 30-d
\n" ); document.write( ".
\n" ); document.write( "Three years ago:
\n" ); document.write( "d-3 = Dina's age then
\n" ); document.write( "c-3 = Cora's age then
\n" ); document.write( ".
\n" ); document.write( "Cora was 3 times as old as Dina.
\n" ); document.write( ".
\n" ); document.write( "c-3 = 3*(d-3)
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\n" ); document.write( "Substitute
\n" ); document.write( ".
\n" ); document.write( "(30-d) -3 = 3(d-3)
\n" ); document.write( "30 -d -3 = 3d -9
\n" ); document.write( "27 -d = 3d -9
\n" ); document.write( "36 = 4d
\n" ); document.write( "d = 9
\n" ); document.write( ".
\n" ); document.write( "c = 30-9
\n" ); document.write( "c = 21
\n" ); document.write( ".
\n" ); document.write( "Check your work?
\n" ); document.write( "3 years ago, was Cora 3 times Dina's age?
\n" ); document.write( ".
\n" ); document.write( "21-3 = 18
\n" ); document.write( "9-3 = 6
\n" ); document.write( "Yes. 3*6 = 18.
\n" ); document.write( ".
\n" ); document.write( "Answer: Currently, Cora is 21 and Dina is 9.
\n" ); document.write( ".
\n" ); document.write( "Done. \n" ); document.write( "

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