t0mek sais "the simplest form", but the comment is fixable by changing that to "a simplest form". (For example, if hypothetically a/b and c/d where somehow the same number, and yet somehow there is no x such that a/b = xc/xd, the argument about how 2 divides into a and b also applies to c and d.)
> Rational numbers or fractions must have a simplest form.
They make no claim about uniqueness, but that is not needed in the argument.