Find the coordinates of the other endpoint

​Point A is located at ( -1 , -5 ). The midpoint of segment AB is point C at ( 2 , 3 ).

What are the coordinates of point B?

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The x-coordinate of the midpoint is (x1 + x2)/2   {x1 and x2 are the x-coordinates of the endpoints}
2 = (-1 + x2)/2   {substituted 2 in for x-coordinate of the midpoint and -1 in for x-coordinate of endpoint}
4 = -1 + x2  {multiplied each side by 2}
5 = x2  {added 1 to each side}
The x-coordinate of the other endpoint is 5.

The y-coordinate of the midpoint is (y1 + y2)/2   {y1 and y2 are the y-coordinates of the endpoints}
3 = (-5 + y2)/2  {substituted 3 in for y-coordinate of midpoint and -5 in for y-coordinate of endpoint}
6 = -5 + y2  {multiplied each side by 2}
11 = y2  {added 5 to each side}
The y-coordinate of the other endpoint is 11.

The coordinates of B are (5,11)

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