Let me first tell u to how find the midnumber of two integers , look :
The midnumber of 3 and - 5 is finding like this :
( 3 + ( -5) ) ÷ 2 =
( 3 - 5 ) ÷ 2 =
- 2 ÷ 2 = - 1
Thus the midnumber of -5 & 3 is - 1 ;
Got it ?
This is what we do exactly to find the coordinates of the midpoint of two points.
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As we have :
A = ( - 5 , 3 )
B = ( 3 , - 1 )
Midpoint of A & B = ( [ -5 + 3] ÷ 2 , [ 3 - 1 ] ÷ 2 )
Mp of A & B = ( -2 ÷ 2 , 2 ÷ 2 )
Mp of A & B = ( - 1 , 1 )