6:7(3+4)

To simplify the expression \( 6:7(3+4) \), we will first calculate the expression inside the parentheses:

1. Calculate \( 3 + 4 \): \[ 3 + 4 = 7 \]

2. Now substitute back into the expression: \[ 6:7(7) \]

3. The notation \( : \) typically means division. So, we rewrite the expression: \[ 6 \div 7 \times 7 \]

4. Now, calculating \( 6 \div 7 \times 7 \), we simplify: \[ 6 \div 7 \times 7 = 6 \]

So, the final result is: \[ \boxed{6} \]