k/(a- 1/x)+(b- 1/x)/(c- 1/x)& lt; 0
Let y =-1/x.
Then the inequality we want to solve becomes:
k/(y+a)+(y+b)/(y+c)& lt; 0
And the title means y∈(-2,-1) ∩ (2,3).
So the solution of X can get X ∈ (1/2, 1)∨(- 1/2,-1/3).