Answer:
k = 3
XY = 33
YZ = 48
Step-by-step explanation:
X___Y___Z
XZ= XY + YZ
81 = (12k-3) + (3+15k)
81 = 27k
27k = 81
k= 81/27
XY= 12k-3 = 12(3) - 3 = 36 - 3 = 33
YZ = 3+15k = 3 + 15(3) = 3 + 45 = 48
I hope I helped you^_^
