3(n-m) - 2(n+1) = 3n - 3m - 2n - 2 = n - 3m - 2 = 1/2 - 3(-2/3) - 2 = (1/2)×3 - (6/3)×2 - 2×6 = 3/6 - 12/6 - 12/6 = 3/6 = 0,5