Chapter 2 - Section 2.5 - Powers of 10 - Exercises - Page 122: 23

$\frac{1}{10^4}$

$\frac{10^3\times10^2\times10^{-7}}{10^5\times10^{-3}}\longrightarrow$ to multiply powers of 10, add the exponents $=\frac{10^{3+2+(-7)}}{10^{5+(-3)}}$ $=\frac{10^{-2}}{10^2}\longrightarrow$ to divide powers of 10, subtract the exponents $=10^{-2-2}$ $=10^{-4}$ $=\frac{1}{10^4}$