\[\boxed{\mathbf{967.\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ (6;\ + \infty)\]
\[x > 6\]
\[x_{\min} = 7.\]
\[2)\ \lbrack 6;\ + \infty)\text{\ \ }\]
\[x \geq 6\]
\[x_{\min} = 6.\]
\[3)\ ( - 3,4;\ + \infty)\]
\[x \geq - 3,4\]
\[x_{\min} = - 3.\]
\[4)\ \lbrack - 0,9;\ + \infty)\ \]
\[x \geq - 0,9\]
\[x_{\min} = 0.\]