Simplify the expression:  $\frac{1}{y^9}\cdot y^{16}$  

Simplify the expression. Only use positive exponents.  $a^{-2}b^{-4}$  

Simplify the expression:

 $\left(5xy\right)^2$  

Simplify the expression:

 $\left(-\frac{6}{b}\right)^2$  

Evaluate the expression:

 $\left(4x^0y^{-5}\right)^2$  

Simplify:  $\frac{\left(a^2\cdot6b^{-4}\right)^3}{\left(a^{-1}\right)^{-1}}$  

Is  $\frac{x^3}{7}$  the simplified form of  $\frac{7x^6\cdot7^{-2}}{\left(\left(x^3\right)^{-1}\right)^{-1}}$  ?

 $\frac{a^2b}{ab^2}$  

 $\left(a^2\right)^3\left(a^{2^3}\right)$