Posted by Annia on Wednesday, December 9, 2009 at 4:44pm.
This Christmas,your brother Jack will be 2 years from being twice as old as your sister Jen.The sum of Jack's age and three times Jen's age is 66.How old is Jen?

Math  PsyDAG, Thursday, December 10, 2009 at 11:05am
Let x = Jack's age
Let y = Jen's age
From the information above:
2y = x  2
x + 3y = 66
Get x on one side for the first equation.
x = 2y + 2
Substitute 2y + 2 for x in the second equation and solve for y. Put that value in the first equation to solve for x. Check by inserting both values into the second equation.
I hope this helps.