Q.

The solution set of the rational inequality x+9x-6≤0 is

1 (-∞,9)∪(6,∞)  
2 (-∞,9]∪(6,∞)  
3 (-∞,9]∪[6,∞)  
4 [-9, 6)  

Ans.

(4)

We have, x+9x-6≤0

Case I: x+9≥0 and x-6<0

⇒ x≥-9 and x<6⇒-9≤x<6            …(i)

Case II: x+9≤0 and x-6>0⇒x≤-9 and x>6

which is not possible simultaneously.

∴  Required solution set is  [-9, 6).