To apply the Power Rule of Exponents, you use the formula \((a^m)^n = a^{m \cdot n}\).
In this case, you have \((15^6)^2\).
Using the Power Rule: \[ (15^6)^2 = 15^{6 \cdot 2} = 15^{12} \]
Thus, the expression equivalent to \((15^6)^2\) is \(15^{12}\).
The correct response is: 15 superscript 12 baseline.