Question

Provide the missing reason in the following proof.


Prove –(–y – x) – x = y
Statements Reasons
–(–y – x) – x = –[–y +(–x)] – x Definition of subtraction
–[–y +(–x)] – x = y + x – x Opposite of a sum property
y + x – x = y + x + (–x) Definition of subtraction
y + x + (–x) = y + [x + (–x)] Associative Property of Addition
y + [x + (–x)] = y + 0 Additive Inverse Property
y + 0 = y ________________________