Question 1088348: Shania is 4 times as old as Jenny. Jenny is 3 years older than Enrique. If their total age is 57, how old will Jenny be in four years ?
I tried the following:
S = 4x
J = x +3
E = x
4x+x+3+x=57
not sure how to continue from here...
thank you
Found 3 solutions by josmiceli, jim_thompson5910, MathTherapy:
Answer by josmiceli(19441)   (Show Source):
Answer by jim_thompson5910(35256)  (Show Source):
You can put this solution on YOUR website! E = Enrique's current age
J = Jenny's current age
S = Shania's current age
Given: "Shania is 4 times as old as Jenny"
Translation: S = 4*J
Call this equation (1)
Given: "Jenny is 3 years older than Enrique"
Translation: J = E+3
Call this equation (2)
Given: " their total age is 57"
Translation: E+J+S = 57
Call this equation (3)
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Focus on equation (3). That equation is E+J+S = 57
Let's make a few replacements or substitutions
E+J+S = 57
E+J+4*J = 57 ... replace S with 4*J (see equation (1) above)
E+E+3+4*(E+3) = 57 ... replace every J with E+3 (see equation (2) above)
Now solve for E
E+E+3+4*(E+3) = 57
E+E+3+4*E+4*3 = 57
6*E+15 = 57
6*E+15-15 = 57-15
6*E = 42
6*E/6 = 42/6
E = 7
Currently, Enrique is 7 years old.
Go back to equation (2). Plug in E = 7 to find J
J = E+3
J = 7+3
J = 10
So currently Jenny is 10 years old.
Extra (optional) info: if J = 10, then using equation (1) we can say S = 4*J = 4*10 = 40, so Shania is currently 40 years old. Note how E+J+S = 7+10+40 = 57 so that checks out.
The question is asking " how old will Jenny be in four years ?", so we simply add 4 to the value of J to get J+4 = 10+4 = 14.
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Final Answer: 14
Answer by MathTherapy(10552)  (Show Source):
You can put this solution on YOUR website!
Shania is 4 times as old as Jenny. Jenny is 3 years older than Enrique. If their total age is 57, how old will Jenny be in four years ?
I tried the following:
S = 4x
J = x +3
E = x
4x+x+3+x=57
not sure how to continue from here...
thank you
It's very, very SIMPLE. You just need 1 (ONE) variable.
Let Jenny's age be J
Then Shania's is 4J, and Enrique's is: J - 3
We then get: J + 4J + J - 3 = 57
6J = 57 + 3
6J = 60
J, or Jenny is: 
So, in 4 (four) years, Jenny will be: 
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