Question

point M with coordinates (3,4) is the midpoint of the line AB and A has the point (-1,6). what is the point of B?

Answer 1

B = (7, 2)

Explanation:

B = 2M -A

B = 2(3, 4) -(-1, 6) = (2·3-(-1), 2·4-6)

B = (7, 2)

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The expression for the other end point, B, comes from the equation for the midpoint.

M = (A +B)/2

2M = A + B . . . . . multiply by 2

2M -A = B . . . . . . subtract A to get an expression for B