Question

Помогите ГИА плиииззззз

Answer 1

$2^{n+2}21^{n+3}/6^{n+1}7^{n+2}=2^{n+2}3^{n+3}7^{n+3}/2^{n+1}3^{n+1}7^{n+2}=$
$2^{n+2-n-1}3^{n+3-n-1}7^{n+3-n-2}=2^{1}3^27^1=126$