[tex]\boxed{\text{Recall: } a^{b} \cdot a^{c} = a^{b + c}}[/tex]
[tex]\text{Thus, } 2.7^{-3} \cdot 2.7^{4} = 2.7^{-3 + 4} = 2.7[/tex]
[tex]3.8^{3} \cdot 3.8^{2} = 3.8^{5}[/tex]
[tex]\therefore 2.7^{-3} \cdot 3.8^{2} \cdot 2.7^{4} \cdot 3.8^{3} = 2.7 \cdot 3.8^{5}[/tex]