SOLUTION: The question is: "Five years ago Paul was 3 times as old as Erin. Now he is twice as old as Erin How old are they?" I made a chart on the information like my math teacher tau

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Question 714742: The question is:
"Five years ago Paul was 3 times as old as Erin. Now he is twice as old as Erin How old are they?"
I made a chart on the information like my math teacher taught me and I got the following (I don't know if it is right):
People Now 5 years ago
Paul 2(n) 3(n-5)
Erin n n-5
I don't know what to do for the equation in order to solve for 'n'.
Thank you for your help!
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Use TWO variables. The problem description gives ways to relate the ages of the two people.

Let p = paul's age 5 years ago
Let e = erin's age 5 years ago

We do not know either of their ages. NOW is ADDITIONAL 5 years, which is why you find some use of addition in the "NOW" column.

PEOPLE _______________NOW_________________5 Years Ago
Paul__________________%28p%2B5%29=2%28e%2B5%29________p=3e
Erin_____________________e%2B5______________e

The table shows, as taken directly from the description and assignment of variables, TWO equations and TWO unknown variables. Our system to begin with is obviously this:

SYSTEM:--------------
p%2B5=2%28e%2B5%29
p=3e
---------------------

WHAT TO DO NEXT
Using the second equation to substitute for p into the first equation is a simple matter. p%2B5=2%28e%2B5%29, %283e%29%2B5=2%28e%2B5%29,
3e%2B5=2e%2B10
3e-2e=10-5
highlight%28e=5%29, 5 years ago.

and it follows that p=3e=3(5)=15, highlight%28p=15%29, 5 years ago.