Answer:
2. 3
3. 4^45
Step-by-step explanation:
[tex]{ ({5}^{4} ) }^{m} = {5}^{12} \\ = > {5}^{4m} = {5}^{12} \\ = > 4m = 12 \\ = > m = \frac{12}{4} \\ = > m = 3 \\ \\ number \: of \: books \: at \: library \\ = {({4}^{9})}^{5} \times {4}^{0} \\ = {4}^{45} \times 1 \\ = {4}^{45} [/tex]
