A = 5/4 - 3/16 = 20/16 - 3/16 = 17/16
B = 1 - 17/15 = 15/15 - 17/15 = -2/15
C = -1,3/-8 + 23/-1,6 = 2,6/16 - 230/16 = 2274/160 = 1137/80
D = 1/3 × -4/5 = -4/15
E = (1/2 - 3/4) × 16/9 = (2/4 - 3/4) × 16/9 = -1/4 × 16/9 = -1/1 × 4/9 = -4/9
F = 5/7 : -15/2 = 5/7 × -2/15 = 1/7 × -2/3 = -2/21
H = 1 : -19/20 = 1 × -20/19 = -20/19
