Question

Solve 10 3/4 - 6 4/5

Answer 1

Alright, so the first thing I would do is find the LCM of the dividends, which is 20.  So we have 10 15/20 and 6 16/20.  You can either leave it there and just carry the one (20 in this case) for 3 19/20.
If you multiply 10 by 20 and add 15, or 6 by 20 and add 16 (which I think is easier) you get 215/20 - 136/20 = 79/20.  It can be simplified from here if you teacher wants it in the future.

Answer 2

Solve; 43/4(×5) - 34/5(×4) = 215/20 - 136/20 = 79/20 [ Answer is 79/20 ] Good Luck! :)