JB is a median
CI is a median
JW=6x+2
JB=10x+1
If W is the centeroidof the triangle, determined by medians JB, CI and KA, it means that it cuts both line segments following the ratio 2:1 → meaning that the segment JW is 2/3 of the segment JB while the segment WB is 1/3 of JB.
This means that the ratio between segments JW and JB is as follows:

Replece it with the given expressions:

Use cross multiplication between both fractions:

And finally solve for x

The unknown value is x=2
Now you can calculate the length of segment JW as:

The length of segment JW is 14 units.