The answer is 9, to find it just do inverse and in this case that is 12-3 and u should always get the answer
Answer: They are inverses of each other
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Explanation:
We'll need to compute h(f(x)) and f(h(x)) to see if we get x each time.

and,

Both composite functions lead to x each time.
The equations h(f(x)) = x and f(h(x)) = x being true means each function is the inverse of the other.
1. 6
2. 4
3. 5
4. area
5. perimeter
6. 12
7. 16
8.
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Area = 14
The borders enclose 14 squares that are 1 long and 1 unit wide.