\( 1 \leftarrow \quad \) Simplify the exponential expression. \( \left(5 y^{6}\right)^{2} \) \( \left(5 y^{6}\right)^{2}=\square \)

To simplify the expression \( \left(5 y^{6}\right)^{2} \), you apply the power of a product rule, which states that when you raise a product to a power, you raise each factor to that power. So, we have: \[ \left(5 y^{6}\right)^{2} = 5^{2} \cdot (y^{6})^{2} = 25 \cdot y^{12} \] Therefore, the simplified form is: \[ \left(5 y^{6}\right)^{2} = 25 y^{12} \]