To solve the equation \((x^?)^2 = x^{54}\), we start by simplifying the left side of the equation.
Using the property of exponents \((a^m)^n = a^{mn}\), we can rewrite \((x^?)^2\) as:
\[ x^{2?} \]
Now our equation looks like this:
\[ x^{2?} = x^{54} \]
Since the bases are the same, we can set the exponents equal to one another:
\[ 2? = 54 \]
To solve for \(?\), we divide both sides by 2:
\[ ? = \frac{54}{2} = 27 \]
Therefore, the value of \(?\) is:
\[ \boxed{27} \]