a) 21,2+1,56-20,4=19,64-20.4= -0,76
b) 1,3-15,64+4,8= -16,94 +4,8= -12,14
c) 1,5 - 2,(3) - 0,(6) = 15/10 - 2 [tex] \frac{3}{9} [/tex] - 6/9 = 3/2 - 21/9 -2/3 =
= 3/2 - 7/3 - 2/3= 3/2 - 9/3 = 3/2 - 3 = 3/2 - 6/2 = -3/2
d) 0,(3)-2,5+7/6= 3/9 -25/10 +7/6 = 1/3 - 5/2 + 7/6 = 2/6 - 15/6 +7/6 = -6/6 = -1
