Answer:
-2 < x < 3
Step-by-step explanation:
-14 < 7x < 21
Divide all three sides by 7 :
[tex]-14 < 7x < 21[/tex]
[tex]\Longleftrightarrow \frac{-14}{7} < \frac{7x}{7} < \frac{21}{7}[/tex]
[tex]\Longleftrightarrow -2 < x < 3[/tex]
The solution in interval notation (-2 , 3)