Please help me- I understand this but not fully

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"

Afamily has two cars. the first car has a fuel efficiency of 25 miles per gallon of gas and the second has a fuel efficiency of 15 miles per gallon of gas. during one particular week, the two cars went a combined total of 1025 miles, for a total gas consumption of 55 gallons. how many gallons were consumed by each of the two cars that week?

Find the value of x. also give me an explanation so i can complete it to other questions as well, : )