We can notice that : Line Passes through the Points (0 , 3) and (1 , 0)
Let us find the slope of the line in order to write the Equation of the Line.
Slope of a Line Passing through two points (x₁ , y₁) and (x₂ , y₂) is given by :

Points are (0 , 3) and (1 , 0)
here x₁ = 0 and x₂ = 1 and y₁ = 3 and y₂ = 0

As the line passes through (0 , 3) , The y - intercept is 3
We know that Equation of line is given by : y = mx + c
where m is the slope and c is the y-intercept
here m = -3 and c = 3
Equation of the Given line : y = -3x + 3
⇒ -3x - y = -3
⇒ 3x + y = 3
As the Given line is a Dotted line and the Shaded Region is Towards the Origin
The Inequality of the Graph is : 3x + y < 3