Question

The midpoint of AB isM(7,−7). If the coordinates of AA are (8, -6), what are the coordinates of BB

Answer 1

B(6 , -8)

Explanation:

let B be the point of coordinates

`(x_B \ , \ y_B)`

M is the midpoint of AB

Then

`x_M=(x_A+ x_B)/(2) \ \text{and} \ \ y_M=(y_A+ y_B)/(2)`

Then

`x_B=2x_M- x_A \ \text{and} \ \ y_B=2y_M- y_A`

Then

`x_B=2(7)- 8=14-8=6 \ \text{and} \ \ y_B=2(-7)- (-6)=-14+6=-8`