Question 86888
You can make 2 equations out of this based on the information given. The first equation is derived from the fact that right now, Erin is 3 times older than Warren. Let E=Erin's age this year, and W=Warren's age this year:
Equation #1: E=3W
The next equation is developed from the fact that in 4 years, Erin will be twice the age of Warren. Using the same variables, you can write:
Equation #2: E+4=2(W+4)
Now that you have 2 equations and 2 unknowns, you can solve this problem!
Substitute the value of E from Equation #1 into Equation #2 and solve for W:
{{{3W+4=2(W+4)}}}
{{{3W+4=2W+8}}}
{{{W+4=8}}}
{{{highlight(W=4)}}}
Now, substitute this value of W into Equation #1 to find Erin's age:
{{{E=3*4}}}
{{{highlight(E=12)}}}
Good Luck,
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