$${\text{If }}{\left( {\frac{3}{5}} \right)^3} \times {\left( {\frac{3}{5}} \right)^{ - 6}} = $$    $${\left( {\frac{3}{5}} \right)^{2x - 1}}{\text{,}}$$   then x is equal to?

$$\eqalign{ & {\left( {\frac{3}{5}} \right)^3} \times {\left( {\frac{3}{5}} \right)^{ - 6}} = {\left( {\frac{3}{5}} \right)^{2x - 1}} \cr & \Rightarrow {\left( {\frac{3}{5}} \right)^{3 - 6}} = {\left( {\frac{3}{5}} \right)^{2x - 1}} \cr & \Rightarrow - 3 = 2x - 1 \cr & \Rightarrow 2x = - 2 \cr & \Rightarrow x = - 1 \cr} $$