Perhaps UK is the median.

2(UK) = VT + RS

2(3x+2) = (4x-6) + (x+12)

6x + 4 = 5x + 6

x + 4 = 6

2(UK) = VT + RS

2(3x+2) = (4x-6) + (x+12)

6x + 4 = 5x + 6

x + 4 = 6

**x = 2**