If the number of faces of a polyhedron is 8 larger than the number of vertices, and it has 30 edges, then the number of vertices of the polyhedron is

If the number of faces of a polyhedron is 8 larger than the number of vertices, and it has 30 edges, then the number of vertices of the polyhedron is

Let the vertex number be x, then the number of faces is x + 8, which is obtained from Euler formula
X+X+8=30+2
The solution is x = 12
A: the number of vertices is 12