Plzzzz help. Giving brainlist and 20 pts.

Answer:
The value of AC = 5 units
Step-by-step explanation:
Given the triangles
In the diagram,
We know that two triangles are termed as similar if their corresponding angles are congruent and the corresponding sides are in proportion.
Therefore,
AB : XY = AC : XZ
AB / XY = AC / XZ
as
so we can determine AC as the ratios of the side become
4 / 6 = AC / 7.5
AC = 4/6 × 7.5
= 5 units
Therefore, the value of AC = 5 units