How to solve 4/7 to -2 power without exponents

\((\frac47)^{-2}=\frac{4^{-2}}{7^{-2}}=\frac{7^2}{4^2}=\frac{7*7}{4*4}\)

 

 

And...   \(\frac{7*7}{4*4}=\frac{49}{16}\)  :)