It means your solving for x
I think this is factorials
so an example would b....... 1*2*3*4*5.... ect
hope this helps
This seems to be dividing by 4, so the next numbers are 20, and then 5. If there is a 3rd, it's 1.25
4x - 1 < 11
Add 1 to both sides
4x < 12
Divide both sides by 4
x < 3
x is less than 3
if you don't have a Unit Circle yet, this is a good time to get one, you can find many online, check maybe in yahoo images, or google images.
Check the picture below.
notice the section encircled in purple.