Using the vertex of the quadratic function, it is found that:
a) The maximum number of customers in the store is at 12 P.M.
b) 75 customers are in the store at this time.
The number of customers in x hours after 7 AM is given by:

Which is a quadratic equation with coefficients 
Item a:
The maximum value, considering that a < 0, happens at:

Hence:

5 hours after 7 A.M, hence, the maximum number of customers in the store is at 12 P.M.
Item b:
The value is y(5), hence:

75 customers are in the store at this time.
A similar problem is given at brainly.com/question/24713268
Answer:
Step-by-step explanation:
The lady gets paid $8 per hour that the shop is opened, so multiply the pay rate ($8) by the amount of hours the shop is opened
$8 * 8 = $64
Now add the $64 onto the expense of running the shop
$64 + $240 = $304
Now take that amount away from Friday's sales
$530 - $304 = $ 226
Profit($226) = Income($530) - Expenses($304)
$226 = $226
=)
Answer:
-7.8k - 7.2
Step-by-step explanation:
Distribute 0.6 to the terms in the parentheses:
0.6(-13k - 12)
-7.8k - 7.2
So, the simplified expression is -7.8k - 7.2