Respuesta :

Answer:

M= ([-1],[1/2])

The number in the green box is -1

Step-by-step explanation:

M= ([x1+x2/2], [y1+y2/2])

M= ([2+(-4)/2], [5+1/2])

M= ([-2/2, 6/2])

M= ([-1, 3])