document.write( "Question 456050: molly is 4 years younger than heidi.in 3 years,heidi will be twice as old as molly.how old are they now ? \n" ); document.write( "

Algebra.Com's Answer #313064 by oberobic(2304) $\"\"$ $\"About$

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m = Molly's age now.
\n" ); document.write( "h = Heidi's age now.
\n" ); document.write( "Molly is 4 years younger than Heidi.
\n" ); document.write( "So, if you subtract 4 from Heidi's age, you will know Molly's age.
\n" ); document.write( "m = h-4
\n" ); document.write( ".
\n" ); document.write( "\"In three years...\"
\n" ); document.write( "(m+3) will be Molly's age then.
\n" ); document.write( "(h+3) will be Heidi's age then.
\n" ); document.write( "(h+3) = 2(m+3) :: given.
\n" ); document.write( ".
\n" ); document.write( "Subsitute what we know about m, which is it equal h-4.
\n" ); document.write( ".
\n" ); document.write( "(h+3) = 2(m+3)
\n" ); document.write( "(h+3) = 2m + 6
\n" ); document.write( "substitute m=h-4
\n" ); document.write( "(h+3) = 2(h-4) +6
\n" ); document.write( "h +3 = 2(h -4) +6
\n" ); document.write( "h +3 = 2h -8 +6
\n" ); document.write( "h +3 = 2h -2
\n" ); document.write( "h = 2h -8 +3
\n" ); document.write( "-h = -5
\n" ); document.write( "h = 5
\n" ); document.write( "Heidi is 5 years old now.
\n" ); document.write( ".
\n" ); document.write( "m = h-4
\n" ); document.write( "m = 5-4
\n" ); document.write( "m = 1
\n" ); document.write( "Molly is 1 years old now.
\n" ); document.write( ".
\n" ); document.write( "Check this answer by testing how old they will be in 3 years?
\n" ); document.write( "Molly will be 8.
\n" ); document.write( "Heidi will be 4.
\n" ); document.write( "Will Molly be twice as old as Heidi?
\n" ); document.write( "Yes.
\n" ); document.write( ".
\n" ); document.write( "Done. \n" ); document.write( "

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