Find the coordinates of point A, symmetric point B (-1; 2) relative to point O (1; 0).

Let’s find the distance along the X-axis from the abscissa of point B to point O:

1) 1 – (-1) = 2 (units).

Point B is removed to the left of point O by 2 units along the X-axis. This means point A must be removed to the right of point O by 2 units as well. Let’s find its coordinates:

2) 1 + 2 = 3 (units).

Let’s find the distance along the Y-axis from the ordinate of point B to point O:

3) 2 – 0 = 2 (units).

Point B is removed upward from point O by 2 units along the Y-axis. This means point A must be removed downward from point O by 2 units as well. Let’s find its coordinates:

4) 0 – 2 = -2 (unit).

Answer: A (3; -2).