It is false that 5/1 and 5 are reciprocal numbers.
Reciprocal or multiplicative inverse is the inversion or flipping of numbers, that is, flipping numerator(upper value) to become denominator(lower value) as well as flipping denominator to become numerator.
Given:
5/1
reciprocal of 5/1 is 1/5
5
5 is same as 5/1
reciprocal of 5 is 1/5
Therefore, it is false that 5/1 and 5 are reciprocal numbers.
