123 49 76
a) -------- + --------- - ------- =
22 11 33
369+174+152 391
------------------------ = -------------
66 66
b) 85 13 15
------- + --------- - --------- =
12 48 24
85 13 5
-------- + --------- - ------ =
12 48 8
340+13-30 323
---------------------- = -----------
48 48