The profit P will be the difference between the earnings and the material cost.
B
We can choose how many bracelets to sell.
C
The break even will occurs when P=0.
A
P=3.5b-84
B
Independent: Profit P Dependent: Number of bracelets b
C
24 bracelets
Practice makes perfect
We decide to make and sell bracelets. The cost of our materials is 84 dollars and we charge 3.5 dollars per bracelet. We want to write a function that represents the profit P for selling b bracelets. To do so, notice that our earnings will be the product of 3.5 multiplied by the number of bracelets b.
Earnings=3.5b
Since we spend 84 dollars for the materials, the profit P will be the difference between the earnings and the material cost.
P=3.5b-84
Recall the function obtained in Part A.
P=3.5b-84
Notice that the profit depends of how many bracelets we sell. This means that P is the variable dependent.
The value of b is also variable, but it is the variable independent because we can choose how many bracelets to sell.
Consider that we will break even when the cost of our materials equals our income. The break even will occurs when the profit is equal to zero.
0=3.5b-84
We want to find the number of bracelets that we need to sell to break even. To do so, let's solve the above equation to b.
