Answer:

Step-by-step explanation:
The complete question in the attached figure
we have

we know that
(ab)(x) is equal to the product of a(x) and b(x)
so

Applying distributive property



This is a quadratic equation
The other expressions not produce a quadratic equation
<span>commutative property of addition
answer is
</span><span>A. 12 + 6 + 15 = 12 + 15 + 6</span>
It d because one x-value correspond two different y-values
The answer is going to 328.5 or 328.50 is the same thing
The total cost for a 6-month plan for n lines is represented by the equation:
Cost = 660n + 100
This equation is in the slope intercept form. The coefficient of n represents the slope here.
In the given scenario the slope can be interpreted as the total variable cost for one line for a period of 6 months.
The variable costs are associated with a line are:
1) Unlimited data cost ($40 per month). So for 6 months this cost will be $240
2) Unlimited Call cost ($10 per month). So for 6 months this cost will be $60
3) Unlimited Text Message Cost ($10 per month). For 6 months this cost will be $60.
4) Cost of Phone ($300 per line)
Adding these costs up we get: 240 + 60 + 60 + 300 = $660
Thus, 660 represents the total cost per line for unlimited data, calls, text message and one phone for 6 months. Therefore, option A gives the correct answer.