10 7/12 - 9/12=(10/12+7/12)-9/12=17/12-9/12=8/12
127/12-9/12
Nope. Her solution doesn't seem reasonable. In order to subtract 9/12 from 10 7/12 you must convert 10 7/12 to an improper fraction. You should then have 127/12 where she has 10/12.
Hope this helps! =)
