(x-2)(x+3)(x-4)>0
x=2 x=-3 x=4
_ + _ +
--------------(-3)------------(2)------------------(4)-----------------
x∈(-3;2) U (4;∞)
(x-1)(x+2)/(x-5)²≤0
x=1 x=-2 x=5
+ _ + +
---------------[-2]------------------[1]----------------(5)----------------
x∈[-2;1]