Definitions:

The additive inverse is the opposite of the number. Any number plus its additive inverse equals 0. $$a + ( -a ) = 0$$ The multiplicative inverse is the reciprocal of the number. Any nonzero number multiplied by its reciprocal equals 1. $$a *\frac{1}{a} = 1$$

 

Note: a cannot = 0

A general example to help you recognize patterns and spot the information you're looking for

Addition: $$7 + ( -7 ) = 0$$ Multiplication: $$7 * \frac{1}{7} = 1$$

Paying back borrowed money.