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
1st problem:
A = 630 cm
2nd problem:
A = 104 cm
All I can see on the picture you provided.
Answer:
Solving the system of equations:
x: 1
y: 2
Step-by-step explanation:
Plug it in to see if it is right, to make sure of course. Better to be safe than sorry.
it would be > because the square root of 2 is more than 1.
6x+4/5=8
subtract 6x from both sides
4/5=8-6x
multiply both sides by 5 to get rid of the fraction
4=40-30x
divide both sides by 2
2=20-15x
add 15x to both sides
15x+2=20
subtract 2 from both sides
15x=18
divide both sides by 15
x=1.2