Bonsoir,
a) 550
550/2 =275
275/5 =55
55/5=11
=> 2*5*5*11 =2*5²*11
b) 320
320/2 =160
160/2 =80
80/2 =40
40/2=20
20/2=10
10/2=5
=>2*2*2*2*2*2*5 = 2^6*5
c) 425
425//5 =85
85/5 =17
=> 5*5*17 = 5²*17
d) 1000
1 000/2 =500
500/2 = 250
250/2 125
125/5 =25
25/5 =5
=>2*2*2*5*5*5 = 2³ *5³