A car rental agency advertised renting a car for $ 26.95 per day and $ 0.28 per mile. if brad rents this car for 4 ​days, how many whole miles can he drive on a $ 250 ​budget?

Let m = the number of miles Brad can drive. Your equation becomes:

250 = 26.95(4) + 0.28m

Now we just solve for m

250 = 107.80 + 0.28m
142.20 = 0.28m

m ≈ 507.857 miles

We are looking for WHOLE miles though and if he goes even a decimal point over that many miles (and change), he will be over budget. Thus, we must round down to the whole integer. 

Brad can drive 507 miles on a $250 budget for a 4-day rental.