An electrician drives 4 miles round trip each day to his job. he can travel 300 miles before he needs to refill his car. he has already driven 100 miles. which inequality gives the number of days, d, he can drives to work before he needs to refill his car?

Round trip = 4 Miles 
Total Distance = 300 Miles 
Miles already Driven = 100 Miles. 

300 Miles - 100 Miles =200 Miles. 
200 Miles / 4 Miles = 50 (Miles cancel put). So, he can drive his car for the next 50 days according to the equation. (There is no set/particular equation for these kid of problems).

The year before the 10s so it was like when caveman were alive