Răspuns:
Explicație pas cu pas:
C) 2 2/5 • ( + 7/3 ) - ( - 5/6 ) • 2 2/5=
12/5 • ( + 7/3 ) - ( - 5/6 ) • 12/5 =
4/5 • ( + 7/1 ) - ( - 1/1 ) • 2/1 =
28/5 - ( - 2/1 ) =
28/5 + 10/5 = 38/5
sau ...
12/5 • [7/3 - ( -5/6)]=
12/5 • ( 14/6 + 5/6 ) =
12/5 • 19/6 = 2/5 • 19/1 = 38/5
D) - 2/9 • ( - 4 2/3) - 2/9 • ( - 2/5 ) + 2/9 • ( - 3 2/5 ) =
-2/9 • (-14/3) - 2/9 • ( -2/5) + 2/9 • ( -17/5)=
28/27 - ( - 4/45 ) + (-34/45) =
28/27 + 4/45 - 34/45=
140/135 + 12/135 - 102/135 =
152/135 - 102/135 = 50/135 = 10/27