Bonjour,
15/8 est irréductible
15/9 = (5 * 3)/(3 * 3) = 5/3.
20/33 est irréductible
21/33 = (7 * 3) / (3 * 11) = 7/11.
72 = 9 * 8
72 = 3 * 3 * 4 * 2
72 = 3 * 3 * 2 * 2 * 2.
144 = 9 * 16
144 = 3 * 3 * 4 * 4
144 = 3 * 3 * 2 * 2 * 2 * 2.
242 = 121 * 2.
2 205 = 45 * 49
2 205 = 9 * 5 * 7 * 7
2 205 = 3 * 3 * 5 * 7 * 7.
