The quotient of 78,600 and 12 is 6,550
If it's a regular octahedron, then you can calculate it using the formula

where

is the length of the edge.
If it's not regular, you have to calculate the area of each side individually.
profit = revenue - expenses
Filling in the given values, where n is the number of necklaces Sam must sell ...
... 1000 = 10n - (5n +5000)
... 6000 = 5n . . . . . . collect terms, add 5000
... 1200 = n . . . . . . . divide by 5
The appropriate choice is
... D. 1200



Use the symmetric property to flip the sides of the equation.

Divide everything by 5.
