Question

Va rog ajutati-ma. Multumesc!

Answer 1

$\frac{1}{9}<\frac{(n+1)^{2}}{27}<\frac{2}{3}$
$\frac{3}{27}<\frac{(n+1)^{2}}{27}<\frac{18}{27}$
$3<(n+1)^{2}<18$
$(n+1)^{2}\in\{4,9,16\}$
$n+1\in\{2,3,4\}$
$n\in\{1,2,3\}$