If A#B=A+B+AB. If for any A there is a number C such that A#C=A, then C=?

Explanation

To solve the problem, we start with the operation defined as \( A \# B = A + B + AB \). We need to find a number \( C \) such that for any \( A \), the equation \( A \# C = A \) holds true.

### Step-by-Step Solution:

1. **Write down the operation**: According to the problem, we have:
\[ A \# C = A + C + AC \]
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