So that would be the same thing as 5 4/5 - 3 2/7
Put them in mixed fractions to become 29/5 - 23/7
Multiply one side by 7 and one side by 5 to get the same denominator
203/35 - 115/35
Now subtract the numerators to get
88/35
Or if they want it inixed numbers then 2 18/35
Getting at least a 80% ( B average) is also good still very close to 90
