We are given the coordinates of a polygon and are requested in the first step to draw its image. The plot is shown below:
We are then asked to draw the image that results from reflecting this polygon over the y-axis. So we recall that such reflection changes the coordinate of the points as shown below:
(x, y) --> (-x, y) changing the x coordinate to its opposite and keeping the y coordinate intact.
Then the transformation of the vertices would be:
J = (2, 2) --> J' = (-2, 2)
K = (7,4 ) --> K' = (-7, 4)
L = (9, -2) --> L' = (-9, -2)
M = (3, -1) --> M' = (-3, -1)
These new vertices are plotted below in red: