If we use a simple example, the additive inverse of 5 is -5. This is because -5 + 5 = 0.
It is the same with fractions, if we take one half, [tex]-\frac{1}{2}[/tex] + [tex]\frac{1}{2}[/tex] = 0
A rational number is a number that can be written as an integer or a fraction without having a 0 in the denominator.
("In mathematics, a rational number is a number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. ")
Basically, the sum of a fraction / rational number and its additive inverse is equal to 0 because you are adding together "opposites" with regards to negative / positive. They are the same number, just different sides of the number line.
