Function 1
Let us calculate the equation of the line of function 1 picking any two points
The two points picked are (1 , 0) and (0 , -4)
The formula for the equation given two points is

Given:

Hence,

Therefore, the equation for the function is

Where, the coefficient of x is the slope and the constant variable is the y-intercept.
Hence,

Function 2
Let us calculate the equation of the line of function 2 picking any two points from the data in the table.
The two points picked are (-2 , 8) and (2 , -12)
Therefore,

Hence,

Where,

Function 3
The given equation is

Function 4
Given:

Hence,
a) The functions that have graphs with slopes less than 3 are Function 2, Function 3 and Function 4.
b) The function that has the graph with a y-intercept closest 0 is Function 3.
c) The function that has the graph with greatest y-intercept is Function 4.