Уровень 1.
№2
3-x≤5
-x≤5-3
-x≤2
x≥ -2
4x-2<8<br>4x<8+2<br>4x<10<br>x<2.5<br>
{x≥-2
{x<2.5<br> \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
--------- -2 -------------- 2.5 ---------
//////////////////////////////////
x∈[-2; 2.5)
Уровень 2.
№1.
1) x-9<8x+5<br> x-8x<5+9<br> -7x<14<br> x> -2
x∈(-2; +∞)
2) 4(x-11)-5(2x-7)≥0
4x-44-10x+35≥0
-6x-9≥0
-6x≥9
x≤ -1.5
x∈(-∞; -1.5]
3) x/3 +9≤x
x+27≤3x
x-3x≤-27
-2x≤-27
x≥13.5
x∈[13.5; +∞)