Prove two exponential functions g & h with positive coefficients & bases b_{g} & b_{h} have the same order of growth if b_{g}=b_{h}>1, & b_{g} has a higher order of growth than b_{h} if b_{g}>b_{h}>1.
So you mean as t -> infinity? If that is the case then get the model and evaluate it as the limit of t tends to infinity and see if it blows up (becomes infinite in magnitude) or converges to a fixed value.