+118724 $$97000=71127e^{0.073t}\\\\
\frac{97000}{71127}=e^{0.073t}\\\\
ln\left(\frac{97000}{71127}\right)=ln e^{0.073t}\\\\
ln\left(\frac{97000}{71127}\right)=0.073t(lne)\\\\
ln\left(\frac{97000}{71127}\right)=0.073t\\\\$$
You should be able to finish it. If you want me to check your answer I can to that. 
+118724 $$97000=71127e^{0.073t}\\\\
\frac{97000}{71127}=e^{0.073t}\\\\
ln\left(\frac{97000}{71127}\right)=ln e^{0.073t}\\\\
ln\left(\frac{97000}{71127}\right)=0.073t(lne)\\\\
ln\left(\frac{97000}{71127}\right)=0.073t\\\\$$
You should be able to finish it. If you want me to check your answer I can to that.
