Question 875169
Uniform rates involving volume of fuel and distance.  FUEL EFFICIENCY is the rate and the route in one direction has some different conditions than in the other direction.


{{{R=D/V}}}, unit is kilometers per liter.  Same as {{{RV=D}}}.



WAY__________Rate__________Distance__________Volume
Out_________x+4_____________200______________v-5
In___________r______________200______________v


We can use the fundamental relation rule to express r better:


WAY__________Rate__________Distance__________Volume
Out_________x+4_____________200______________v-5
In___________200/v__________200______________v


Nothing more is possible from this data.  Clearly the two routes differ because the fuel volumes are not equal for the same path or road; and the fuel efficiency rates cannot be equal:  {{{x+4<>200/v}}}.
More information is needed.  Do you see a way to obtain a quadratic equation in only x?