Hello,
224 = 112 * 2
224 = 16 * 7 * 2
224 = 8 * 2 * 7 * 2
224 = 2 * 2 * 2 * 2 * 2 * 7
224 = 7 * 2^5
280 = 140 * 2
280 = 70 * 2 * 2
280 = 35 * 2 * 2 * 2
280 = 7 * 5 * 2 * 2 * 2
280 = 7 * 5 * 2^3
224/280 = (7 * 2^5)/(7 * 5 * 2^3) = (2 * 2)/(5) = 4/5
Il s'agit de l'inverse de 224/280 donc on a : 280/224 = 5/4