Answer/Step-by-step explanation:
a. Using two points on the line (0, 2) and (4, 12), find the gradient:
Gradient = ∆y/∆x = (12 - 2) / (4 - 0) = 10/4 = 2.5
Gradient = 2.5
b. The gradient, 2.5, represents the unit rate. That is, the volume of the oil in the tank per second.
i.e. 2.5 litres per second
c. The value, L = 2 represents the y-intercept, which is the starting value or initial volume of oil in the tank at 0 secs.
T = 30h + 84l
C = h + 2l
P = h + 4l
C = 18h + 36l
P = 12h + 48l
If the 2 given points are endpoints, then we're in business. The formula for the midpoint is

. If the endpoints of our segment are the coordinates (1,2) and (12,14), our formula would be filled in as follows:

which simplifies to (13/2, 8). See? It's pretty simple once you know how to do it.
V = 30*16*12. To find the volume of a rectangular prism, you just multiply the area of the base (side 1 * side 2) by the height of the prism.