Answer:
3. Ø
Step-by-step explanation:
[tex]|a|=a\ \text{for}\ a\geq0\\\\|a|=-a\ \text{for}\ a<0[tex]|x|+7<4\qquad\text{subtract 7 from both sides}\\\\|x|+7-7<4-7\\\\|x|<-3\to x\in\O\ \text{because}\ |x|\geq0\ \text{for any value of }\ x.[/tex]===================[/tex]
