The given expression is:
[tex](8.5\text{ }\times10^8)\text{ }\times\text{ (2.5}\times10^6)[/tex]This can be expressed as:
[tex]\begin{gathered} (8.5\times2.5\times10^8\times10^6) \\ 21.25\times(10^8\times10^6) \\ \text{Note: a}^b\times a^c=a^{b+c} \\ \text{Therefore, the expression becomes:} \\ 21.25\times10^{14} \\ 2.125\times10^1\times10^{14} \\ 2.125\times10^{15} \end{gathered}[/tex]