225k views
5 votes
Given the endpoint A(1, 3) and the midpoint C(6, 2), find the other endpoint B(x, y).

Group of answer choices
(11, 1)

(3.5, 2.5)

(7, 5)

(6, 12)

User UmmaGumma
by
4.2k points

1 Answer

6 votes

Right away we know we don't have fractions; the midpoint is the average of the coordinates, so if it and one endpoint are integers so is the other endpoint.

We can do a kind of point arithmetic:

C = (A+B)/2

2C = A+B

B = 2C - A

B = 2(6,1) - (1,3) = (12,2)-(1,3)=(11,-1)

Answer: That's none of the above, but a typo away from the first choice.

User Ulfelder
by
3.7k points