help me.............

a. [tex] {3}^{ - 5} \times ( \frac{ {3}^{3} }{ {3}^{ - 4} } ) = {3}^{ - 5} \times ( {3}^{3 + 4} ) = {3}^{ - 5} \times {3}^{7} = {3}^{2} [/tex]

b. [tex] \frac{ {2}^{ - 2} }{ {2}^{4} } = {2}^{ - 2 - 4} = {2}^{ - 6} = \frac{1}{ {2}^{6} } [/tex]

c. [tex]( {0.25})^{ - 2 + 4} = (0.25)^{2} [/tex]