1
{5x-4<0⇒5x<4⇒x<0,8<br>{13/(9x²-16)<0⇒9x²-16<0⇒(3x-4)(3x+4)<0⇒-4/3<x<4/3<br>x∈(-4/3;0,8)
2
{(x²-9)/(2x²+3)>0⇒(x-3)(x+3)>0⇒x<-3 U x>3
{(2x-4)/(x²-2x-8)<0⇒2(x-2)/(x-4)(x+2)<0⇒x<-2 U 2<x<4<br>x=2 x=-2 x=4
_ + _ +
----------(-2)-------(2)------(4)----------------
x∈(-∞;-3) U (3;4)