B. 180cm3
You have to find length, width, and height of both objects.
For the first one multiply:
3 x 8 x 5 = 120
Then multiply:
2 x 5 x 6 = 60
Add them together:
120 + 60 = 180cm3
Here, we are missing the slope and the y intercept.
Lets look for the y intercept first.
Where does it cross the y axis? At 3!!
3 is the y intercept.
Now, find the slope by using the slope formula.

(0,3) and (2,1)
m = 1-3/2-0 = -2/2 = -2/2 = -1
m = -1
Okay, so we found our slope, now just write the equation.
Answer: y = -1x + 3