Number of brown trout = 6
Number of lake trout = 18
Total number of trouts = 
Probability to catch a lake trout first time = 
As the fisherman let the trout go, so probability for the second time is =

Hence, the probability becomes=

= 
The probability to find the brown trout is 
as , 
= 
The answer is $9.59 as one bag is $1.37 so time that by seven and you get that
For this case what you should do is observe the classic graph of supply and demand.
In this graph, we are going to visualize only the demand curve.
Two facts are met for the claim:
1) If the price is high, the quantity demanded decreases.
2) If the price is low, the quantity demanded increases.
Answer:
The lower prices imply an increase in the quantity demanded.
Are you sure that one of the variables is v and not y?
v+4= -2(x-1)
Since you posted v, I will use v in place of y.
v + 4 = -2x + 2
v = -2x + 2 - 4
v = -2x - 2
Done!