Answer:
(a) Equation: 
(b) 7.5 gallons
Step-by-step explanation:
Given
Current Gas = 10 gallon
Every Hour = -1.25 gallon
Solving for (a): An equation for the scenario
This question represents an Arithmetic Progression and will be solved using the following formula:

Where


Substitute these values in the formula


Collect Like Terms


Solving for (b): In this case, n - 3
Substitute 3 for n in 



<em>7.5 gallon of gas left</em>
Answer:
A≈50.27cm²
Step-by-step explanation:
Cuboid C is 4 and 4. Cuboid D is 2 and 4.
The notation just means
(f/g)(-4) = f(-4) / g(-4)
If f(x) = x² + 2 and g(x) = 1 - 3x, then
f(-4) = (-4)² + 2 = 16 + 2 = 18
g(-4) = 1 - 3 (-4) = 1 + 12 = 13
and so
(f/g)(-4) = 18/13