Can someone teach how to do this?

Answer:
V = 15
Step-by-step explanation:
We are given the number of faces and edges and we are to find the number of vertices.
We know the formula that relates the number of faces, number of vertices and the number of edges:
F + V - E = 2
Substituting the given values to find V (number of vertices):
25 + V - 38 = 2
V - 13 = 2
V = 15