1)
/////////////////////////////////////////////
--------(1)-------------------(2,5)--------------
\\\\\\\\\\\\\\\\\\\\\\\\\\
x∈(2,5;∞)
2){x≥1,5
{x≤3
//////////////////////////////////////////////////////
---------[1,5]----------------------[3]---------------
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
x∈[1,5;3]
3
/////////////////////////////////////////////////////
------------(-2)---------------------(-1,5)----------------
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
x∈(-2;-1,5)
4
{5x<5⇒x<1<br>{x<12<br>\\\\\\\\\\\\\\
---------(1)---------------------(12)-----------
///////////////////////////////////////////
x∈(-∞;1)
5
{x≤15
{x≥6
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
--------[6]------------------[15]-----------
/////////////////////////////////////////
x∈[6;15]
6
{x>0
{x≥-7
/////////////////////////////////////////////
----------[-7]--------------------(0)----------------
\\\\\\\\\\\\\\\\\\
x∈(0;∞)