Answer:
Step-by-step explanation:
(2.7)(10)
=27
27^4=531441
-------------------------------
(3.5)(10)
=35
35^3=42875
To combine like terms and single out one term to take it easier to solve, the 6x was moved to the other side to combine like terms.
Subtracting 6x from 10x which is 4x
In the left hand side, you're multiplying 7.8 by 
In the right hand side, you're multiplying again 7.8 by a mysterious number.
So, the unknown number must be 
Every number remains unchanged when multiplied by 1, so the answer is 3.6
Answer:
The water temperature that produces the maximum number of salmon swimming upstream is approximately 12.305 degrees Celsius.
Step-by-step explanation:
Let
, for
.
represents the temperature of the water, measured in degrees Celsius, and
is the number of salmon swimming upstream to spawn, dimensionless.
We compute the first and second derivatives of the function:
(Eq. 1)
(Eq. 2)
Then we equalize (Eq. 1) to zero and solve for
:

And all roots are found by Quadratic Formula:
, 
Only the first root is inside the given interval of the function. Hence, the correct answer is:

Now we evaluate the second derivative at given result. That is:


According to the Second Derivative Test, a negative value means that critical value leads to a maximum. In consequence, the water temperature that produces the maximum number of salmon swimming upstream is approximately 12.305 degrees Celsius.