Can somebody pleas explain how i do this

equation given


calculations
add 8 to both sides 
divide both sides by 6/7...
which means multiply by 7/6 

So now you have 

(Excuse me, I'm not used to the wonky LaTeX on this site...)

In all honesty, there really is no “work” per say to show. mainly it’s just using the process of elimination. the question is asking which domain(s) would be the most appropriate for the function c(n). n is the number of observed vehicles so right away, 1, 2, and 3 can be eliminated.why? 1, 2 start in the negatives and therefore it is impossible to observe negative cars. so, #4 would be the best answer to the given problem.