Explicație pas cu pas:
a:b= 2006, rest 13
a= 2006b+13
a) (2020+2·a)+(3·a-10030·b)=
inlocuim pe a cu a= 2006b+13
[2020 + 2(2006b+13) + 3(2006b+13)-10030b)]=
(2020+ 4012b+26 ) + (6018b +39- 10030b)=
2046 + 4012b + 39 -4012b= 2085
b) a-b<30088
2006b+13-b<30088
2005b<30088-13
2005b<30075
b<30075:2005
b<15
b = 1,2,3,4,5 6,7,8,9,10,11,12,13,14
b=1
a= 2006x1+13= 2006+13= 20019
b=2
a= 2006×2+13= 4025, etc