Question

determinati numerele prime a,b,c stiind ca 2*a+7*b+6*c=78.

Answer 1

2a + 7b + 6c = 78
2a,6c,78 divizibile cu 2 => 7b divizibil cu 2,b = prim => b = 2
2a + 14 + 6c = 78
2a + 6c = 78 - 14 = 64
2(a + 3c) = 64
a + 3c = 64 : 2 = 32
1) c = 2 => a + 6 = 32 => a = 32 - 6 = 26 (F)
2) c = 3 => a + 9 = 32 => a = 32 - 9 = 23
3) c = 5 => a + 15 = 32 => a = 32 - 15 = 17
4) c = 7 => a + 21 = 32 => a = 32 - 21 = 11
5) c = 11 => a + 33 = 32 (F)
raspunsurile sunt : a,b,c = 23,2,3
a,b,c = 17,2,5
a,b,c = 11,2,7

Answer 2

Sper ca te-am ajutat ! :)