Given point A(-6, 7) is the midpoint B(A, 4) and point C(0, b). What is the values of a and b?

Answer 1

xC = ( xA + xB ) / 2

yC = ( yA + yB ) / 2

In this case:

xA = - 6 , yA = 7

xB = a , yB = 4

xC = 0

yC = b

xC = ( xA + xB ) / 2

0 = ( xA + xB ) / 2

( - 6 + xB ) / 2 = 0

Multiply both sides by 2

- 6 + xB = 0

Add 6 to both sides

xB = 6

xB = a

a = 6

yC = ( yA + yB ) / 2

Since yC = b

b = ( 7 + 4 ) / 2

b = 11 / 2