Let's begin by listing out the information given to us:

We are to find the value of y
Answer:
lesss go
Step-by-step explanation:
Answer:
y= 126
Step-by-step explanation:
The given equation is: y= 3x-2x^2+5x^3
Substituting the value x=3 in the above equation,we get
y= 3(3)-2(3)^2+5(3)^3
⇒y= 9-2(9)+5(27)
⇒y= 9-18+135
⇒y= 126
Answer: 233 min
Step-by-step explanation:
This problem can be solved by the following equation:
(1)
Where:
is the quantity left after time 
is the initial quantity
is the time elapsed
is the constant of decay for the material
So, firstly we need to find the value of
from (1) in order to move to the next part of the problem:
(2)
Applying natural logarithm on both sides of the equation:
(3)
(4)
(5)
(6)
(7) Now that we have the value of
we can solve the other part of this problem: Find the time
for
.
In this case we need to isolate
from (1):
(8)
(9)
Finally: