1558 : n = a r 58
n × a = 1558 - 58 = 1 500
526 : n = b r 26
n × b = 526 - 26 = 500
1043 : n = c r 43
n × c = 1043 - 43 = 1 000
1 500 = 2^2 × 3 × 5^3
500 = 2^2 × 5^3
1 000 = 2^3 × 5^3
_______________
cmmdc = 2^2 × 5^3 = 4 × 125 = 500
n = 500
_______
1 558 : 500 = 3 rest 58
526 : 500 = 1 rest 26
1 043 : 500 = 2 rest 43