Let's start with triangle RST. This is a 30-60-90 triangle, which means it has the relationship x - x sqrt(3) - 2x.
If RS is 2 sqrt(3), then ST must be 2 and RT must be 4.
Triangle QRT is a 45-45-90 triangle, which means it has the relationship x - x - x sqrt(2).
If RT is 4, then RQ must also be 4.
Answer: x = 4
Hope this helps!
