given the coordinates of endpoint A (4, -7) and midpoint M (-2, -3) find the coordinates of B, the other endpoint in segment AB

Question

anonymous · Answer

Find change from A to M 
(-6,4)

add it to M
we get
(-8,1)

myininaya · Answer

$$(2(-2)-4,2(-3)-(-7))=(-4-4,-6+7)=(-8,1)$$

anonymous · Answer

$$x_{midpoint}=(1/2)(x_1+x_2)$$
so:
-2=(1/2)(4+x)
-4=4+x
-8=x
$$y_{midpoint}=(1/2)(y_1+y_2)$$
so
-3=(1/2)(-7+y)
-6=-7+y
1=y
b(-8,1)

anonymous · Answer

Three different method( I think), you get to choose

myininaya · Answer

$$(endpointx_1,endpointy_1)=(2(midpointx)-endpointx_2,2(midpointy)-endpointy_2)$$