4,49 - (6,21 + 3,3) + (6,7 - 4,49) + 6,21
1) (6,21 + 3,3)= 9.51 2) (6,7 - 4,49) = 2. 21 3) 4,49 - 9.51= -5.02 4) 2. 21+ 6,21= 8.42 5)8.42-5.02= 3.4