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.
idk what kind of math problem but, if its just simple id us PEMDAS
Answer:
12 hours
Step-by-step explanation:
If we assume that the units of D are kg, then we can put the given number into the equation and solve.
21 = h +9
12 = h . . . . . subtract 9
Eli worked 12 hours to prepare 21 kg of dough.