Question

What is the value of the expression 3.9 times 10^5 /1.3 times 10^2

Answer 1

$\bf ~~~~~~~~~~~~\textit{negative exponents} \\\\ a^{-n} \implies \cfrac{1}{a^n} \qquad \qquad \cfrac{1}{a^n}\implies a^{-n} \qquad \qquad a^n\implies \cfrac{1}{a^{-n}} \\\\ -------------------------------\\\\ \cfrac{3.9\times 10^5}{1.3\times 10^2}\implies \cfrac{3.9}{1.3}\times \cfrac{10^5}{10^2}\implies 3\times 10^5\cdot 10^{-2}\implies 3\times 10^{5-2} \\\\\\ 3\times 10^3\implies 3.0\times 10^3$