M = [ 1/6 + 2/9 + 3/4] /3 = [ (6+8 + 27)/36]/3 = 41/36×1/3 = 41/108
M = [3/7 + 1/5 + 1/3]/3 =[ (45 + 21 +35)/105]/3 = 101/105×1/3 = 101/315
M = (1,2 + 0,15 + 3 +4)/4 = 8,35/4 = 2,0875
M = [1,(5) + 0,1(5) + 1,5]/3 = [14/9 + 7/45 + 3/2] /3 = [(140 +14 + 135)/90]/3 = 298/90×1/3 = 298/270
