Question

Sally's house is located at (5, −1) and her school is located at (−9, 7). Her best friend Molly lives at the midpoint of Sally's house and school. What coordinate represents Molly's house? A. (2, −3) B. (−2, 3) C. (3, −2) D. (−3, 2)

Answer 1

B. (-2, 3)

Explanation:

Given two coordinates (x₁, y₁) and (x₂, y₂), the coordinate of their midpoint is equivalent to X = (x₁+x₂)/2 and Y = (y₁+y₂)/2.

Given the coordinate of Sally's house and her school to be (5, −1) and (−9, 7) respectively, the midpoint of Sall's house and school is expressed as shown;

from the coordinates, x₁ = 5, y₁ = -1, x₂ = -9 and y₂ = 7

X = (5+(-9))/2

X = 5-9/2

X = -4/2

X = -2

Y = -1+7/2

Y = 6/2

Y = 3

The coordinate of the midpoint of Sally's house and school will be expressed as (X, Y) which is equivalent to (-2, 3).