Bonsoir,
Ex. 29 :
117 ÷ 3 = 39
39 ÷ 3 = 13
donc 117 = 3 × 3 × 13 = 3² × 13
132 ÷ 2 = 66
66 ÷ 2 = 33
33 ÷ 3 = 11
donc 132 = 2 × 2 × 3 × 11 = 2² × 3 × 11
357 ÷ 3 = 119
119 ÷ 7 = 17
donc 357 = 3 × 7 × 17
1 547 ÷ 7 = 221
221 ÷ 13 = 17
donc 1 547 = 7 × 13 × 17
