Question

Найдите все целые n, при которых 19n+7/7n+11 - целое число

Answer 1

$frac{19n+7}{7n+11}= frac{2(7n+11)+5n-15}{7n+11}=2+frac{5n-15}{7n+11}, \ left [ {{5n-15=0,} atop {5n-15=7n+11;}} right. left [ {{n=3,} atop {n=-13.}} right.$