When Ella shifts the hexagon 7 units to the left, we need to modify the x-coordinates of the points of the hexagon. To shift a point to the left by 7 units, we subtract 7 from the x-coordinate.
Therefore, the correct function that Ella would write for this translation would be:
f(x) = x - 7
This means that for any x-coordinate of the hexagon, the new x-coordinate after translation will be found by subtracting 7.
So, the correct response is: f(x) = x - 7