Question

The midpoint of line CD is E(-1,0). One endpoint is C(5,2). What are the coordinates of the other endpoint

Answer 1

Let's call the other endpoint D(x, y).

We know that the x-coordinate of the midpoint E is the average of the x-coordinates of the endpoints C and D:

(5 + x)/2 = -1

Simplifying the equation, we have:

5 + x = -2
x = -7

Similarly, the y-coordinate of the midpoint E is the average of the y-coordinates of the endpoints C and D:

(2 + y)/2 = 0

Simplifying the equation, we have:

2 + y = 0
y = -2

Therefore, the coordinates of the other endpoint D are (-7, -2).