1/25 + 43/50 = 2/50 + 43/50 = 45/50 = 9/10 = 0,9
1/5 - 47/10 = 2/10 - 47/10 = 45/10 = 9/2 = 4 1/2 = 4,5
2/5 * 9/8 = 1/5 * 9/4 = 9/20 = 0,45
12/5 : 15/2 = 12/5 * 2/15 = 4/5 * 2/5 = 8/25 = 0,32
(1/6 + 1/4) * 9 = (2/12 + 3/12) * 9 = 5/12 * 9 = 5/4 * 3 = 15/4 = 3 3/4 = 3,75
(3/8 - 1/20) * 10 = (15/40 - 2/40) * 10 = 13/40 * 10 = 13/4 = 4 1/4 = 4,25
(1 11/16 - 3 7/8) * 4 = (1 11/16 - 3 14/16) * 4 = (27/16 - 62/16) * 4 = - 35/16 * 4 = - 35/4 = - 8 3/4 = - 8,75
0,9 / 1 + 1/5 = 0,9 / 1 + 0,2 = 0,9/1,2 = 0,75