Respuesta :

The given sum is -8 + 17.

The second expression 17 + (-8) is equivalent to 17 - 8, and also it's equivalent to -8 + 17. B is correct.

The third expression is -8 + 8 + 9 which is equivalent to -8 + 17 because 8 + 9 = 17. C is correct.

Therefore, the right answers are B and C.