To simplify the expression \((7^2) / (7^5)\), we can use the property of exponents that states \(\frac{a^m}{a^n} = a^{m-n}\).
Applying this property:
\[ \frac{7^2}{7^5} = 7^{2-5} = 7^{-3} \]
Thus, \((7^2) / (7^5) = 7^{-3}\), not \(7^{12}\).
So, we conclude that the equation you're considering is incorrect, and the simplified expression results in \(7^{-3}\). Hence, there is no missing number to make \((7^2) / (7^5) = 7^{12}\) true.
If you need further clarification or assistance, feel free to ask!