Math solve pls no links

Answer:
[tex]1) {b}^{ - 4} \div {b}^{9} \\ = {b}^{ - 4} \times {b}^{ - 9} = {b}^{ - 13} =1/b^13\\ 2) \frac{ {4}^{ 5} \times {4}^{ - 8} }{ { {4}^{3} }^{2} } \\ = \frac{ {4}^{ - 3} }{ {4}^{6} } \\ = {4}^{ - 3} \times {4}^{ - 6} \\ = {4}^{ - 9} \\ hank \: you[/tex]
Question 10.
correct option is A
Question 20.
therefore, D is the correct option