Respuesta :

1) 5 + ( 2 + 7) = (5 + 2) + 7

It is the associative property of the addition.

This property states that when adding 3 numbers, the grouping or association of the numbers does not change the result.

2) The second expression is unreabable


3) h + 0 = h


It is the identity property.


This property states that 0 is the identity element of the addition and any number added to  it is equal to the same number.

AS  you know, 5 + 0 = 5, 1234 + 0 = 1234; 0 + 2548 = 2548.