Which number produces a rational number when added to 1/5 ?

By definition, a rational number is:

It is any number that can be represented as the quotient of two whole numbers or, more precisely, an integer and a positive natural.

We have many numbers that added to 1/5 result in a rational number.

For example, we have:

1.4 is a rational number

A number produces a rational number when added to 1/5 is:

the discriminant is 64 + 4*1*12 = 112

this is prime.

step-by-step explanation:

what is the original number? you forgot to add it.