Chapter 5 - Section 5.2 - More Work with Exponents and Scientific Notation - Exercise Set - Page 268: 85

$3.5\times10^{22}$

Using laws of exponents, the given expression simplifies to \begin{align*} & \dfrac{9.24\times10^{15}}{(2.2\times10^{-2})(1.2\times10^{-5})} \\\\&= (9.24\div2.2\div1.2)(10^{15}\div10^{-2}\div10^{-5}) \\\\&= 3.5\times10^{15-(-2)-(-5)} \\\\&= 3.5\times10^{22} .\end{align*}