Y=14
If they are congruent then t=d so write the equation and solve from there, welcome im Procrastinating.
Answer:



Step-by-step explanation:
Given




Required
The dimension that minimizes the cost
The volume is:

This gives:

Substitute 


Make H the subject


The surface area is:
Area = Area of Bottom + Area of Sides
So, we have:

The cost is:



Substitute:
and 



To minimize the cost, we differentiate

Then set to 0


Rewrite as:

Divide both sides by W

Rewrite as:

Solve for 


Take cube roots

Recall that:







Hence, the dimension that minimizes the cost is:



Answer:
-8.5
Step-by-step explanation:
1/4 times 2= 0.5
0.5-9=-8.5
Hope this helps :D