Question 290623: Erica's uncle is three times as old as she is now. Four years ago, he was four times as old as she was then. How old is Erica now?
Found 2 solutions by Earlsdon, MathTherapy:
Answer by Earlsdon(6294)   (Show Source):
You can put this solution on YOUR website! LetU equal Erica's uncle's present age and E = Erica's present age.
U = 3E and
U-4 = 4(E-3) Simplify.
U-4 = 4E-12 Substitute U = 3E.
3E-4 = 4E-12 Add 12 to both sides.
3E+8 = 4E Subtract 3E from both sides.
8 = E
Erica's present age is 8 years.
Answer by MathTherapy(10551)  (Show Source):
You can put this solution on YOUR website! Erica's uncle is three times as old as she is now. Four years ago, he was four times as old as she was then. How old is Erica now?
Let Erica's present age be E, and her uncle's U
Then we'll have U = 3E, since her uncle is three times her present age
Since the uncle's present age is 3E, then four years ago, he was 3E - 4, and Erica was E - 4 years-old. Since he was four times her age then, we'll then have:
3E - 4 = 4(E - 4)
3E - 4 = 4E - 16
-E = - 12
Therefore, E, or Erica is currently  years-old.
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