What would be the midpoint to be in geometry

Iwant to know what 3g+5h+4g-2h is my teacher is too selfish to tell us

Ineed someone to me answer my question i have to have this done and knocked out

Three friends went on a road trip from phoenix, az, to san diego, ca. mark drove 50 percent of the distance. jason drove 1/8 of the distance. andy drove the remainder of the distance. 1. andy thinks he drove 1/4 of the distance from phoenix, az, to san diego, ca. is andy correct? 2. the distance from phoenix, az, to san diego, ca, is 360 miles. how many miles did each person drive? 3. solve the problem. what is the answer in total?