148 more miles before they need to refill the gas tank.
1) Considering that the inequality that represents this situation is:
Notice that in this equation "x" stands for the number of miles that he needs to finish the trip.
2) So we can solve that to find out the number of miles Mikey's family can make with the gas already in the car:
Note that we have subtracted 112 from both sides.
3) Hence, the answer is:
Mikey's family can drive up to 148 miles before they need to refill the gas tank