document.write( "Question 124762: Got another one. I swear A+ hates me.\r
\n" ); document.write( "\n" ); document.write( "Mike is three times as old as his little sister, Mary. In 4 years, he will be twice as old as Mary. How old is Mary?\r
\n" ); document.write( "\n" ); document.write( "I know the equation is:
\n" ); document.write( "M = Mike's age m = Mary's age
\n" ); document.write( "3m = M
\n" ); document.write( " and
\n" ); document.write( "M+4 = (m+4)2 \n" ); document.write( "
Algebra.Com's Answer #91474 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Mike is three times as old as his little sister, Mary. In 4 years, he will be twice as old as Mary. How old is Mary?
\n" ); document.write( "----------------------------
\n" ); document.write( "NOW DATA:
\n" ); document.write( "Let Mike's age be \"3x\" yrs.
\n" ); document.write( "Mary's age is \"x\" yrs.
\n" ); document.write( "----------------------------------
\n" ); document.write( "4 years from NOW DATA:
\n" ); document.write( "Mike's age will be \"3x+4\" yrs.
\n" ); document.write( "Mary's age will be \"x+4\" yrs.
\n" ); document.write( "--------------------
\n" ); document.write( "EQUATION based on 4 yrs from NOW:
\n" ); document.write( "Mike = 2(Mary)
\n" ); document.write( "3x+4 = 2(x+4)
\n" ); document.write( "x = 4 yrs. (Mary's age NOW)
\n" ); document.write( "--------------
\n" ); document.write( "3x = 12 yrs. (Mike's age NOW)
\n" ); document.write( "=================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( " \n" ); document.write( "
\n" );