Question

Given M is the mid-point of AB, find the co-ordinates of A; if M = (1, 7) and B = (–5, 10).

Answer 1

M is the mid-point of AB.

Let A = (x, y), M = (1, 7) and B = (–5, 10)

∴ `1 = (x - 5)/2`

`=>` x – 5 = 2

∴ `x = 2 + 5 = 7` and `7 = (y + 10)/2`

`=>` y + 10 = 14

∴ y = 14 – 10 = 4

∴ Co-ordinates of A are (7, 4)