Răspuns:
1.4a2b apartine {4020,4320,4620,4920,4125,4425,4725}
2.x36y apartine {3360,6360,9360,1362,4362,7362,2364,5364,8364,3366,6366,9366,1368,4368,7368}
3.x12y apartine {6120,2124,7128}
Explicație pas cu pas:
1.
15 l 4a2b => 3 l 4a2b => 3 l 4+2+a+b => 3 l a+b
5 l b => b apartite {0,5}
- b=0 =>3 l a=> a apartine {0,3,6,9} =>4a2b apartine {4020,4320,4620,4920}
- b=5 =>3 l a+2 => a apartine {1,4,7} =>4a2b apartine (4125,4425,4725}
2.
6| x36y =>y apartine {0,2,4,6,8} }=>
3| x+y }
x36y apartine {3360,6360,9360,1362,4362,7362,2364,5364,8364,3366,6366,9366,1368,4368,7368}
3.
36 | x12y => 9|x+y+3 }=> x+y+3 apartine {9,18}=>x+y apartine {6,15}
x+y+3<=21 }
36 | x12y => 4|2y => 4|y
=>x apartine {6,15} => x=6 =>x12y=6120
=>x apartine {2,11} => x=2 => x12y =2124
=>x apartine {-2,7} => x=7 => x12y =7128
=>x12y apartine {6120,2124,7128}
