Answer:
The length of XK = 12.7 
Explanation:
Given that 
JK = 12 , JL = 16 , KX = y + 3 , XL = 2y 
From the Δ JKX
 ----- (1)
 ----- (1)
From the Δ JXL
 ---------- (2)
 ---------- (2)
From Equation (1) & (2) we get
144 - (


By solving above equation we get
y = 9.7 
Therefore the length of XK = y + 3 = 9.7 + 3 = 12.7