To solve the equation \( \frac{7^?}{7^5} = 7^{12} \), we can use the properties of exponents. According to the rules of exponents, when dividing two expressions with the same base, you subtract their exponents:
\[ \frac{7^m}{7^n} = 7^{m-n} \]
Applying this to our equation gives us:
\[ \frac{7^?}{7^5} = 7^{? - 5} \]
Set this equal to \( 7^{12} \):
\[ 7^{? - 5} = 7^{12} \]
Since the bases are the same, we can equate the exponents:
\[ ? - 5 = 12 \]
To find the value of \( ? \), we add 5 to both sides:
\[ ? = 12 + 5 = 17 \]
Thus, the missing number is:
\[ \boxed{17} \]