I cant solve this problem

Answer:
y = 6.5
Step-by-step explanation:
If a line is drawn parallel to one side of the triangle and intersect the other two sides, then the line divides the other two sides in the same ratio.
[tex]\sf \dfrac{BL}{LD}=\dfrac{BK}{KC}\\\\\dfrac{13}{y}=\dfrac{10}{5}\\\\Cross \ multiply,\\\\13*5 = y *10\\\\\dfrac{13*5}{10}=y\\\\\dfrac{13}{2}=y\\\\\boxed{\bf y = 6.5}[/tex]