The equation of any straight line, called a linear equation, can be written as: y= mx+b, where my is the slope of the line and b is the y-intercept. The y-intercept of this line is the value of y at the point where the lone crosses the y axis.
To evaluate a function at a given input, you have to substitute every occurrence of the variable with that particular value.
So, for the first function, you have

The name of the variable is obviously irrelelvant, so the same goes for the second function:

Answer: A. 3072 cm³
Step-by-step explanation:
The formula for determining the volume of a rectangular prism is expressed as
Volume = length × width × height
Looking at the diagram,
Length = 6 cm
Width = 4 cm
Height = 2 cm
When the measures are multiplied by 4, then
Length = 6 × 4 = 24 cm
Width = 4 × 4 = 16 cm
Height = 2 × 4 = 8 cm
Therefore,
Volume = 24 × 16 × 8 = 3072 cm³