You can use the trigonometric identity

.

The requirement that

eliminates -1/6 from being another solution.
4 + 3(10 - 23)
4 + 3 × (-13)
4 - 39
-35 << answer
hope this helps, God bless!
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