Question

6. Find the coordinates of A if M-1, 2) is the midpoint of AB and B
has coordinates of (3.-5).

Answer 1

A(-5,9)

Explanation:

Let A(a,b)

Since M is the midpoint then of A(a,b) and B(3,-5) then

M( (a+3)/2 , (b-5)/2)

But it is given that M(-1,2)

So (a+3)/2 = -1 which implies a=-5

and (b-5)/2=2 which implies b=9.

Therefore A(-5,9)