Subject 1. Determine the prime numbers a<b<c that satisfy the relation
13a+65b+289c=6622
Official solution
## Subject 1.
| The numbers a,b,c cannot all be odd because 6622 is even. Therefore, either they are all even | 2p | | or only one of them is even. | 1p | | a=b=c=2 does not satisfy the relation | 1p | | since a<b<c⇒a=2 | | | we get 65b+289c=6596. The numbers 289 and 6596 have 17 as a common divisor ⇒17 is | | | a divisor of 65b and thus of b. But b is prime ⇒b=17 | 2p | | Finally, c=19. | 1p |
Source: NuminaMath-1.5,
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