how to express 4 to the power 3 (-3)to the power -5 as rational no. ?

Answer : 

We have   4³ $\times$ ( - 3 )^-5 

We can write it in rational form As  : 

$\frac{4^3}{-3^5}$                                                           ( As we know  a^m $\times$ b^-n   = $\frac{a^m}{b^n}$ ) 

And we know rational form is $\frac{p}{q}$  , where q $\ne$ 0  , So ,

$\frac{4^3}{-3^5}$   is our rational form of given number                         ( Ans )