a) [1,3(5) - 0,0(2) + 0.6] - ( 1 intreg si 7/15 - 1/5) =
=[(135-13)/90 - 2/90 + 6/10] - ( 22/15 - 1/5) =
=122/90 - 2/90 + 3/5 - ( 22/15 - 3/15) =
=4/3 + 3/5 - 19/15 =
=(20+9-19)/15=10/15=2/3=0,(6)
b) [0,2(4)+0,1(7)]-{[1,8(3)-2,5(3)]-[-1,1(6)]} =
= [(24-2)/90+(17-1)/90]-{[(183-18)/90-(253-25)/90]-[-(116-11)/90]} =
= (22/90+16/90)-[(165/90-228/90)+105/90]=
= 38/90-42/90=
=-4/90=-2/45=-0,0(4)
