To solve the equation \( 7^{?} \div 7^{5} = 7^{12} \), we can use the properties of exponents.
When you divide two exponentials with the same base, you subtract the exponents:
\[ 7^{?} \div 7^{5} = 7^{(?) - 5} \]
So, we can rewrite the equation as:
\[ 7^{(?) - 5} = 7^{12} \]
Since the bases are the same, we can set the exponents equal to each other:
\[ ? - 5 = 12 \]
Now, we can solve for \( ? \):
\[ ? = 12 + 5 \] \[ ? = 17 \]
Thus, the missing number is \( \boxed{17} \).