OK...here ya go ( image below)    Read carefully so you will understand .....
  
   Pick two convenient points on the line.....see the ones I picked?
    find the slope between these lines      slope = m = (y1-y2)/(x1-x2) =  (1-0) /( 3-1)   = 1/2
       so your line starts to look like    y = mx + b    <====== 'Slope-Intercept' form of a line 
                                                         y = 1/2 x + b      now we need to calculate 'b'     use either of the points in the equation
                                using 3,1           1 = 1/2 (3) + b
                                                              b = - 1/2
                                        Now your line equation is  y = 1/2 x - 1/2 
      the shaded area of the graph is everything GREATER than ( above ) the line
                                y > 1/2 x - 1/2     then re-arrange it into the form needed ( as I did in earlier post )  ......        helpful?
  
  
 