1.
a) 3,47+12,9 = 16,37
b) 1/4 + 1/5 = 5/20 + 4/20 = 9/20
c) 3 1/4 - 3/4 = 13/4 - 3/4 = 10/4 = 2 2/4
d) 1008-179= 829
e) 4/9-1 = 4/9-1/1= 4/9-9/9= - 5/9
f) - 5/8 + 1/3 = - 15/24+8/24= - 7/24
g) -275-(-132)= -143
h) 17 + (-0,14)= 16,86
i) -3,6-4,8= -8,4
