Respuesta :

The coordinate is (-4, 4)

Step-by-step explanation:

Given A( 1 , -2)=( x1, y1)

B( x2 , y2)

Mid point of AB, M ( -2 , 1)

Now we have the formula for the mid point that is

Mid point of AB = [ (x1 + x2)/ 2 , ( y1 + y2) /2]

Or, ( -2 , 1 ) = [ ( 1 + x2) / 2 , ( -2 + y2) / 2]

Now equating with the corresponding elements we get,

-2 = ( 1 + x2) / 2

-4 = 1 + x2

x2 = -4 - 1

x2 = -5

Also

1 =( -2 + y2) / 2

2 = -2 + y2

y2 = 2+2

y2 = 4

Therefore the coordinates of B are ( -5 , 4)

Hope it helps. :)