Answer:
first we know the speed from home to school is 8mph and from school to home is half that speed so 4 miles per hour
now,
from home to school it takes: m/8 hours
and from school to home m/4 hours
we can pass it to minutes multiplying by 60
so:
from home to school it takes: m*7.5 minutes
and from school to home m*15 minutes
and now the relations between these two amount of minutes is that takes 15 more from school to home so:
7.5m+17
Explanation: