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
Answer:
P(A n B) = 5
Step-by-step explanation:
From the venn diagram given, we can see that;
P(A) = 25
P(B) = 15
P(A n B) = 5
Thus,the correct answer of P(A n B) which is the intersection between A and B is 5
Answer:
7(x4) = 8-x
Step-by-step explanation: