Question

The midpoint of is M(2, 7). One endpoint is K(–5, 11). Which equations can be used to find the coordinates of endpoint L?

Answer 1

Use the midpoint formula: ((x_K + x_L)/2, (y_K + y_L)/2) = (2, 7).

So
(-5 + x_L)/2 = 2 and (11 + y_L)/2 = 7.

Solving gives -5 + x_L = 4 → x_L = 9, and 11 + y_L = 14 → y_L = 3.

Thus L = (9, 3).