Answer:
25
Step-by-step explanation:
From the given information;
Numbers of posters that can be printed in an hour = no of impression/hour × no of plate utilized in each impression.
= 1000x
Thus, the required number of hours it will take can be computed as:

cost per hour = 125
If each plate costs $20 to make, then the total number of plate will equal to 40x
∴
The total cost can be computed as:


At C'(x) = 0




x = 25


where; x = 25

C''(x) = 1.6
Thus, at x = 25, C'' > 0
As such, to minimize the cost, the printer needs to make 25 metal plates.
Answer:
slope = 4
Step-by-step explanation:
Calculate the slope m using the slope formula
m = 
with (x₁, y₁ ) = (0, 0) and (x₂, y₂ ) = (3, 12) ← 2 points on the line
m =
=
= 4
The unit rate for 'y' is 1/8 per x .
The unit rate for 'x' is 8 per y .