Question

Determinati numerele prime a,b,c care verifica reletiile:

a) 3a+b+6c=51

Dau multe puncte+coroana

Answer 1

$a,b,c - nr.prime$

[tex]3a+b+6c=51 3a divizibil 3 6c dizivibil 3 si 51 divizibil 3 si b divizibil cu 3 unde b=3 ( numar prim ) 3a+6c=51-3 unde 3a+6c=48 ( imparte la 3 ) a+2c=16 tot aici 2c e divizibil cu 2 si 16 divizibil cu 2 =) deci si a divizibil 2 unde a =2 ( numar prim ) 2c=16-2 2c=14 unde c=14/2 deci c=7 ( numar prim ) [/tex]

Answer 2

3a+b+6c=51
3/3a,3/6c,3/51 =>3/b,b=nr prim=>b=3
3a+3+6c=51|-3
3a+6c=48|÷3
a+2c=16
2/2c,2/16=>2/a,a=nr prim=>a=2
2+2c=16|-2
2c=14|:2
c=7