2020 people formed a line. In one move, you are allowed to exchange the positions of two people, separated by one other person.
1 answer:
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You can rewrite the inequality as
Note that
is the equation of the line drawn in the pictures. This means that, for every point on the line, the y coordinate is exactly image of the x coordinate, i.e.
The inequality is satisfied by all points whose y coordinate exceeds the image of the x coordinate. Since the y axis is positively oriented upwards, a greater value for the y coordinate means that the point has to be higher than the line.
Also, since the equality inlves a and not a
sign, the line itself is excluded.
So, the correct graph is the second one.