Answer:

Step-by-step explanation:
#We use the base diagonal and the height diagonal to calculate the beam's height:

#The volume of the beam can then be calculated as:

Hence, the beam's volume is 
15 miles cause you do 5 times 3 and you get 15 miles
I just did this a few seconds ago and the correct answer is 78. The check above the number is green which means its correct.
When x = 1
5(1) = -y + 6
5 = -y + 6
y = 6 - 5 = 1
When x = 2
5(2) = -y + 6
10 = -y + 6
y = 6 - 10 = -4
When x = 3
5(3) = -y + 6
15 = -y + 6
y = 6 - 15 = -9
I believe the answer is 11/15 .