Calculate the Iterated Integral $$\int _ { 0 } ^ { \ln 4 } \int _ { 0 } ^ { \ln 5 } 3 e ^ { 5 x - y } d x d y$$

Short Answer

Calculate the iterated integral.
$$\int _ { 0 } ^ { \ln 4 } \int _ { 0 } ^ { \ln 5 } 3 e ^ { 5 x - y } d x d y$$