Starting with
[tex]2|x|<10[/tex]
Divide both sides by 2 to get
[tex]|x|<5[/tex]
If [tex]x[/tex] is positive, this means
[tex]x<5[/tex]
If [tex]x[/tex] is negative, this means
[tex]-x<5 \iff x>-5[/tex]
So, we are looking for positive number smaller than 5, or negative numbers greater than -5. In other words, every number between -5 and 5 (both excluded) will satisfy the equation.
