1. Use Euler’s formula to find the number of vertices in a polyhedron with 18 edges and 9 faces
use formula: F+V = E+2

please help!

11 vertices

Step-by-step explanation:

Hi, to answer this question we simply have to substitute E=18 and F= 9 on Euler's formula:

F+V = E+2

Where:

F = number of faces

V = number of vertices

E= number of edges

Replacing with the values given:

9+V = 18+2

Solving for V:

V =18+2-9

V = 11

Feel free to ask for more if needed or if you did not understand something.  

f

step-by-step explanation:

f

yes. we do proportions in probabilities.