Explanation:
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x = 2
This is a vertical line passing through (2, 0) .
y = 4
This is a horizontal line passing through (0, 4).
<, > - dashed line
≤, ≥ - solid line
<, ≤ - shaded to the left (down) from the line
>, ≥ - shaded to the right (up) from the line