Răspunsuri

2014-07-23T15:40:15+03:00
18:9=2
21:9=2r3 adica 2x9+3
dupa urmeaza 3x9+4=27+4=31
31:9=3r4
4x9+5=36+5=41
41:9=4r5
Rezulta ca avem formula
(n-1)*9+n Astfel incat catul va fi mai mic decat restul si cele 2 numere vor fi consecutive.

2014-07-23T16:31:35+03:00
D:9=C+R
D=9C+R
R<9
C<R

R-nr natural
R={1,2,3,4,5,6,7,8}

C-nr natural 
C={2,3,4,5,6,7}

1)R=1 =>C=0   nu este solutie

2)R=2  =>C=1
D=9*2+1=18+1=19

3)R=3  =>C=2
D=9*3+2=27+2=29

4)R=4  =>C=3
D=9*4+3=36+3=39

5)R=5  =>C=4
D=9*5+4=45+4=49

6)R=6  =>C=5
D=9*6+5=54+5=59

7)R=7  =>C=6
D=9*7+6=63+6=69

8)R=8  =>C=7
D=9*8+7=72+7=79