14^-3x14^5 using a single positive exponent

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?

Given the equation f(x)=a(b)x where the initial value is 40 and the growth rate is 20% what is f(4)

The u-drive rent-a-truck company plans to spend $13 million on 320 new vehicles. each commercial van will cost $25 comma 000, each small truck $50 comma 000, and each large truck  $80 comma 000. past experience shows that they need twice as many vans as small trucks. how many of each type of vehicle can they buy?