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?The midpoint of AB is M(1,-4). If the cobrdinates of A are (-3,-6), what arethe coordinates of B?

1 Answer

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Midpoint formula:


(x_M,y_M)=((x_A+x_B)/(2),(y_A+y_B)/(2))

xM = 1

yM = -4

xA = -3

yA = -6

Then:


\begin{gathered} 1=(-3+x_B)/(2) \\ 1\cdot2=-3+x_B \\ 2+3=x_B \\ 5=x_B \end{gathered}
\begin{gathered} -4=(-6+y_B)/(2) \\ (-4)\cdot2=-6+y_B \\ -8\text{ + 6 = }y_B \\ -2=y_B \end{gathered}

The coordinates of B are (5, -2)

User Guettli
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