Chapter 7 - Exponents and Exponential Functions - 7-4 Division Properties of Exponents - Practice and Problem-Solving Exercises - Page 443: 27

=4.2 $\times$ $10^{3}$

You have $\frac{8.4*10^-{^5}}{2 * 10^-{^8}}$.Simplify: $\frac{8.4*10^-{^5}}{2 * 10^-{^8}}$ -subtract the exponents- $10^{-5-(-8)}$=$10^{3}$ $\frac{8.4}{2}$ $\times$ $10^{3}$ -divide the terms- =4.2 $\times$ $10^{3}$