−(7,73−5 7/9)−(0,27−2 2/9).

(7,73-5 7/9)-(0,27-2 2/9)=

. +900

1. 7 73/100-5 7/9=(7-5)-(657-700)

=

900

1 857/900

2. 27/100-2 2/9= - 1 857/900

. +900

2 2/9-27/100=2-(200-243)

=

900

1 857/900

3. 1 857/900-(-1 857/900)=

2 1714/900=3 814/900=3 407/450