document.write( "Question 170711: Mary's age is twice Tom's age and one-third of Sally's age. If the sum of their ages is 99, how old is Mary?
\n" ); document.write( "I feel like this is so easy, but I'm obviously missing something because I can't get the correct answer. Thank you. \n" ); document.write( "

Algebra.Com's Answer #126025 by Mathtut(3670) $\"\"$ $\"About$

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these can be confusing at times. One must first find what is missing....we need Mary's ,Tom's, and Sally's ages, which we will call m,t,and s respectively.
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\n" ); document.write( "so we have 3 unknowns:so lets see if we can come up with 3 equations
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\n" ); document.write( "m=2t............eq 1
\n" ); document.write( "m=(1/3)s..........eq 2
\n" ); document.write( "m+t+s=99........eq 3
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\n" ); document.write( "lets rewrite eq 2 in terms of s and t by plugging in m's value from eq 1 into eq 2 (2t)=(1/3)s
\n" ); document.write( "multiply terms by 3---->6t=s---> now we have m(eq 1) and s(eq 2) in terms of t.
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\n" ); document.write( "so take m's value in eq 1 and s's re written value from eq 2 and plug them into eq 3
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\n" ); document.write( "2t+t+6t=99
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\n" ); document.write( "9t=99
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\n" ); document.write( " $\"highlight%28t=11%29\"$ toms age
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\n" ); document.write( "from eq 1 $\"highlight%28m=2%2811%29=22%29\"$ mary's age
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\n" ); document.write( "from eq 2 $\"highlight%28s=6%2811%29=66%29\"$ sally's age \n" ); document.write( "

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