Respuesta :

we can multiply the normal numbers on the one hand and the scientific notation on the other hand

so

[tex]\begin{gathered} (5\times3)(10^{-6}\times10^{-4}) \\ (15)(10^{-6+(-4)}) \\ =15\times10^{-10}=1.5\times10^{-9} \end{gathered}[/tex]