What is the additive inverse of the expression a - b ?
the additive inverse is what you add to the expression to get 0, like 5 and -5 are additive inverses of each other. the additive inverse of a - b is b - a. that's it! ;)
To explain this, I'll give a bit of background on the terminology first: The inverse of a given expression is the expression which when combined (using a particular operation) with the original expression gives that operation's identity. The identity is the value for the operation which leaves an expression unchanged when it is operated on. For the operation of addition, the identity is zero, because: a+0 a Therefore the additive inverse of a is -a because: a+(-a) a-a 0 Back to your example, and the additive inverse of a-b is -(a-b) b - a. Check: (a-b)+(b-a) a-b+b-a 0 as required. Hope that makes sense.
