To solve the equation \( 7^? ÷ 7^5 = 7^{12} \), we can use the properties of exponents.
When dividing two exponential expressions with the same base, we subtract the exponents:
\[ \frac{7^?}{7^5} = 7^{? - 5} \]
Setting this equal to \( 7^{12} \):
\[ 7^{? - 5} = 7^{12} \]
Since the bases (7 in this case) are the same, we can set the exponents equal to each other:
\[ ? - 5 = 12 \]
Now, solve for \( ? \):
\[ ? = 12 + 5 \] \[ ? = 17 \]
Thus, the missing number is \( \boxed{17} \).