Answer:
$16.
Step-by-step explanation:
Let t represent the cost of each tree.
We have been given that Yuri purchased 8 trees to have planted at his house. So the cost of 8 trees will be 8t.
We are also told that the store charged a delivery fee of $5 per tree. So the delivery charges of 8 trees will be 
The total cost of purchasing 8 trees will be
.
Since the total cost of the trees including the delivery was $168, so we can get an equation as:



Upon dividing both sides of our given equation by 8, we will get:
Therefore, the cost of each tree is $16.
4/6
= 2/3
As we take total and divide by what we looking for
.
2 first class tickets
4 coach tickets
x = 
isolate 5x by adding c to both sides of the equation
5x = k + c ( divide both sides by 5 )
x = 