Rewrite each of the following in the form of a single exponential. \( \begin{array}{lll}\text { (a) } 6^{23} \cdot 6^{15} & \text { (b) }\left(5^{2}\right)^{4} & \text { (c) } x^{6} \cdot z^{6}\end{array} \) \( \begin{array}{ll}\text { (a) } 6^{23} \cdot 6^{15}=6^{38} & \text { (Type your answer using exponential notation.) } \\ \left.\text { (b) } 5^{2}\right)^{4}=\square \text { (Type your answer using exponential notation.) }\end{array} \)

First additional information: To combine \( (5^{2})^{4} \) into a single exponential, use the power of a power property which states that \( (a^m)^n = a^{m \cdot n} \). So in this case, you multiply the exponents: \( 2 \cdot 4 \). Second additional information: For \( x^{6} \cdot z^{6} \), you can notice both terms have the same exponent. This allows you to rewrite it as \( (xz)^{6} \) using the property that \( a^{m} \cdot b^{m} = (ab)^{m} \).