Question 710731
Hello, 
Let x be the age of the house and y represent the garage. We can set up 2 equations as:
x+12=y
3x=y
Substitute:
x+12=3x
Subtract x and divide by 2 to get:
x=6
So now we know the house is 18 years old  and the garage is 6 years old. 
Make sense?
RJ
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