21,4 - 5 1/2 - (16 2/3 - 6,6)

21,4-5 1/2-(16 2/3-6,6)=21,4-5,5-16 2/3+6,6=15,9+6,6-16 2/3= =22,5-16 2/3=22 5/10-16 2/3=22 15/30-16 20/30=21 45/30-16 20/30= =5 25/30=5 5/6