## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$\color{blue}{5.12 \times 10^{-5}}$
Divide the corresponding parts (divide the constants together and the powers of 10 together) to obtain: $=\dfrac{1.28}{2.5} \times \dfrac{10^{-8}}{10^{-4}} \\=0.512 \times \dfrac{10^{-8}}{10^{-4}}$ Use the quotient rule for exponents to obtain: $=0.512 \times 10^{-8-(-4)} \\=0.512 \times 10^{-8+4} \\=0.512 \times 10^{-4}$ Write $0.512$ as $5.12 \cdot 10^{-1}$ to obtain: $=(5.12\cdot 10^{-1}) \times 10^{-4} \\=5.12 \times 10^{-1+(-4)} \\=\color{blue}{5.12 \times 10^{-5}}$