Question

determinati multimile urm si precizati cardinalele lor: A=(x apartine N|(x+1)| 12); C=(x apartine N|(x-1)| 24)

Answer 1

a. x+1 divide pe 12 =>
1. x+1 = 1 iar x=0
2. x+1 = 2 iar x=1
3. x+1 = 3 iar x=2
4. x+1 = 4 iar x=3
5. x+1 = 6 iar x=5
6. x+1 = 12 de unde  x=11

card A = 6

b. x-1 divide pe 24 =>
1. x-1=1 de unde x=2
2.x-1=2 de unde x=3
3. x-1=3 de unde x=4
4. x-1=4 de unde x=5
5. x-1=6 de unde x=7
6. x-1=12 de unde x=13
7. x-1=24 de unde x=25

cardC=7