Respuesta :
take the 12 and split it into 10 + 2.
then you have 10 + 2 - 4.
reorder to get 10 - 4 + 2 (by commutative property)
then you have 6 + 2 = 8
then you have 10 + 2 - 4.
reorder to get 10 - 4 + 2 (by commutative property)
then you have 6 + 2 = 8