Answer:
4/5
Step-by-step explanation:
Cos X = (adjacent side)/(hypotenuse)
The hypotenuse is always the longest side
The adjacent side is the side that makes up the angle that is not the hypotenuse.
For this triangle, the hypotenuse is 15
In relation to Z, the adjacent side is YZ, or 12
So Cos Z = 12/15, which reduces to 4/5
