## Algebra 1: Common Core (15th Edition)

4 $\times$ $10^{4}$
You have f(x)=5000 $\times$ $2^{x}$.Where it represents the investment after x decades.Plug in x=3 since 30 years is 3 decades: f(3)=5000 $\times$ $2^{3}$ f(3)=40000 Put it into scientific notation form :4 $\times$ $10^{4}$