The two functions are 1st degree polynomial, so they are both lines.
In order to draw a line, you have to sample two points and connect them.
To sample points from an equation, choose any value for x and compute the correspondent value for y.
For example, if we choose x=0 and x=1 for the first equation, we have
[tex]f(x)=3x-2 \implies f(0)=-2,\quad f(1)=1[/tex]
So, the line passes through the points [tex](0,-2)[/tex] and [tex](1,1)[/tex]
Similarly, if we choose x=0 and x=3 for the first equation, we have
[tex]f^{-1}(x)=\dfrac{x}{3}+\dfrac{2}{3} \implies f(0)=\dfrac{2}{3},\quad f(3)=1[/tex]
So, this line passes through the points [tex]\left(0,\frac{2}{3}\right)[/tex] and [tex](3,1)[/tex]
If you draw the two points for each line and connect the pairs, you'll have the two lines.
