Answer:
Manufacturers has to produce 63 DVD/Blu-Ray players to achieve a minimum cost of $644
Step-by-step explanation:
The cost equation is given as:

This is a quadratic equation in general form, which is:

Matching, we can say:
a = 0.04
b = -5
c = 800
The minimum occurs at 
and the minimum value would be to place that "x" value into the equation.
First, we find the minimum using values of a and b:

Plugging this into original, we get:

Rounding off to nearest whole number, we can say:
Manufacturers has to produce 63 DVD/Blu-Ray players to achieve a minimum cost of $644
Multiply 240 by 5 to get 1200 miles then add the 40 from the first day so it took 5 days
Answer:
The total number of halves is 4 and the lines are considered as 1/4, 1/2 and 3/4.
Step-by-step explanation:
When both the strips are placed end to end the total number of halves is 4, 2 for each of the paper strips. Lines are as indicated in the figure attached.
Answer: 8x
Step-by-step explanation:
2(3x + x)
2(4x)
8x
Hope this helps.