Answer:
Step-by-step explanation:
From the given triangles in the picture attached,
∠A ≅ ∠X [Given]
∠B ≅ ∠Y [Given]
By AA property of similarity of the triangles, both the triangles will be similar.
ΔABC ~ ΔXZY
Similarity statement:
Corresponding sides of these similar triangles will be proportional.

Similarity ratio:

= 
= 3 : 2
Use pemdas : so do parenthesis first 15-8, then multiply the answer by 6. OR u can use distributive property & multiply 6 by 15 & 8