${\left( \frac{ 199 }{ 20 } \right)}^{-360}$
Express with a positive exponent using ${\left( \frac{ a }{ b } \right)}^{-n}={\left( \frac{ b }{ a } \right)}^{n}$${\left( \frac{ 20 }{ 199 } \right)}^{360}$
To raise a fraction to a power, raise the numerator and denominator to that power$\frac{ {20}^{360} }{ {199}^{360} }$