Which of the following expenses is not a fixed cost?
a. equipment leases
b. packaging costs
c. insurance
d. salary

b.

packaging costs

Step-by-step explanation:

Part A.

The given equation is:

y = x^2 + 6x + 7

By completing the square:

y = (x^2 + 6x + 9) + 7 – 9

y = (x + 3)^2 – 2

y + 2 = (x + 3)^2

Part B.

The vertex form of a parabola is in the form:

y – k = 4p (x – h)^2

Where (h, k) is the vertex (x, y) of the parabola.

Therefore the vertex: (-3, -2)

Since 4p = 1, a positive number, therefore the parabola opens up which makes the vertex (-3, -2) the minima of the graph.

Part C.

The Axis of Symmetry is the x - coordinate of the vertex which is x = - 3