From the diagram, we can see that CL bisects angle JCN. This means that CL divides the angle JCN into 2 equal halves. It means that
angle JCN = angle JCL + angle LCN
Given that angle JCN = 8r - 2 and angle LCN = 3r + 15, it means that
8r - 2 = angle JCL + 3r + 15
Since angle JCL = angle LCN, then
8r - 2 = 3r + 15 + 3r + 15
8r - 2 = 6r + 30
8r - 6r = 30 + 2
2r = 32
r = 32/2
r = 16
angle JCL = 3r + 15 = 3 * 16 + 15
angle JCL = 48 + 15
angle JCL = 63 degrees