Y= 3/5x - 15/5
This should be your answer
None of the answers are correct because it would be 4, 10, 12, 17, then 41
The answer is 1.0929924242
When

, you have

Now assume this is true for

, i.e.

and under this hypothesis show that it's also true for

. You have




In other words, there exists

such that

Rewriting, you have



and this is equivalent to

modulo 9, as desired.
Answer: A cardboard box without a lid is to have a volume of 32,000 cubic cm. Find the dimensions that minimize the amount of cardboard used
. ans: base 40 x 40, height = 20
Solution:
The typical box might look like the one below
where . In addition we have xyz = 32000 ,so we need to minimize .
We have,
From the geometry of the problem so y = x. So or x = 40.
Finally, y = x = 40 and z = 32000/(xy)=20.