\(12=\left(6:3\right)!.5+\left(5-3\right)\)

\(12=3.3+3\)

\(12=\dfrac{6.5}{3}+5-3\)

\(12=\dfrac{5!}{6}-5-3\)

\(12=3!+6\)

\(12=3\sqrt{5.3+6-5}\)

\(12=\dfrac{6.6}{3}\)

\(12=\dfrac{6!}{3!}:\left(5+5\right)\)

12 = 5 + 5 + \(\dfrac{6}{3}\)

12 = \(6\cdot5-6\cdot3\)

12 = \(3\cdot5-3\)

12 = \(6\cdot3-6\)

...

1. 12 = \(6+5+\dfrac{3}{3}\)

2. 12 = \(3+3+6\)

3. 12 = \(\sum\limits^6_3\left(X\right)-6\)

4. 12 = \(\prod\limits^6_5\left(X\right)-3\cdot5-3\)