Question

M(8,7) is the midpoint of Rs. The coordinates of S are (9,5). What are the coordinates of R?

(8.5,6)
(7,9)
(16, 14)
(10,3)
​

Answer 1

Answer is (7,9).

Explanation:

The midpoint formula for a line is (X1+X2/2 , Y1+Y2/2).

Because every answer has a different X coordinate, you only need to calculate one coordinate. I decided to calculate the x coordinate. So... if you apply the formula... X1+9/2 = 8. Multiply two on both sides to get X1+9=16.

X1 is 7.