X³-11x²+39x-45=0
x²(x-3)-8x(x-3)+15(x-3)=0
(x-3)(x²-8x+15)=0
x²-8x+15=0
x1+x2=8 U x1*x2=15
x1=3 U x2=5
x+2=0
x=-2
(x³-11x²+39x-45)/(x+2)≥0
(x-3)²(x-5)/(x+2)≥0
+ _ _ +
--------------(-2)--------[3]----------[5]-----------------
x∈(-∞;-2) U [5;∞) U {3}