1-1 properties of real numbers

Question 1

opposite or additive inverse

Answer 1

any number a is -a. the sum of opposites is 0

Question 2

reciprocal or multiplicative inverse

Answer 2

any non zero number a is 1/a. the product of reciprocals is 1

Question 3

absolute value of a real number

Answer 3

is its distance from zero on the number line