X(x-5)(x-3)>0
x_1 = 0
x_2 = 5
x_3 = 3
- + - +
----------------------------0-------------------------------------3-------------------------5------------------------------>
x∈(0;3)U(5;+∞)
===
7x-3<9x-8<br>7x-9x<-8+3<br>-2x<-5<br>x>2.5
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
-----------------------------------2.5---------------------------->
x∈(2.5;+∞)