Aconvex polyhedron has 30 edges and 8 fewer vertices than faces. how many faces does the polyhedron have?

formula for polyhedrons is V-E+F=2

F= faces = unknown F

V= vertices=F-8

E= edges=30

(F-8)-30+F=2

add the 2 F's and 30 & 8 so you get 2F-38=2

ince -38 doesn't have variable move it to other side by adding 38 to both sides

2F=38+2 which becomes 2F=40

now divide both sides by 2 to get F=20 so there are 20 faces

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x