Use the following formula valid fo every polyhedron.
v-e+f=2
<span>
Search for Euler characteristic, or Euler-Poicare characteristic for more depth about this formula </span>
v= number of vertices
e=number of edges
f=number of faces
<span>You get v=13
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Answer:
See Step by step explanation
Step-by-step explanation:

Answer:
A = 14.2/1.1 hours
B = 5.091 hours
Step-by-step explanation:
Formulate 2 simultaneous equations
5.7A + 6.8B = 111.40..........(1)
A +B =18...............................(2)
Multiply each item in (2) by 5.7 to get
5.7A + 5.7B = 97.2............(3)
subtract (1) - (3) on each side
5.7A -5.7A + 6.8B - 5.7B = 111.40 -97.2
1.1B = 14.2
B = 14.2 /1.1
to get A use equation (2)
A = 18 - B
A = 18 - 14.2/1.1 = 5.091
0.0069
Step-by-step explanation:
6.9 move the decimal 3 places to the left