Question

determinati valorile naturale a lui n,pentru care (2n-1)|(7n+10)

DAU COROANA​

Answer 1

2n-1 | 7n+10     |*2

2n-1 | 2n-1        |*7

scazind cele e ecuatii:

2n-1 | 20+7=27

2n-1 | 27

Divizorii lui 27 sint: 1, 3, 9, 27, -1, -3, -9, -27

Sau 2n-1 ∈ {1, -1, 3, -3, 9, -9, 27, -27}

2n ∈ {2, 0, 4, -2, 10, -8, 28, -26}

n ∈ {1, 0, 2, -1, 5, -4, 14, -13}

Dar n ∈ N, deci n ∈ {0, 1, 2, 5, 14}