(x- 1)/3=0, so x= 1. There are only 1 elements in the set, and there are infinite integers divided by 3, and the remainder is equal to 1.

It should be (x- 1)/3=k, k∈Z, that is, {x|x=3k+ 1, k∈Z}.

Enumeration is a method of listing the elements in a collection one by one and writing them in {} to represent the collection. When the elements in the collection. Description is a method of representing a collection by writing the same attributes of elements in the collection as {0}, which is usually applicable to infinite collections.

Extended data:

Representation method of set

1. Enumeration: commonly used to represent a finite set, in which all elements are listed one by one and written in braces. This method of representing a set is called enumeration. For example, {1, 2, 3, ...}.

2. Description: It is often used to represent an infinite set. The public * * * attribute of the elements in the collection is described by words, symbols or expressions and enclosed in braces. This method of representing a set is called description.

{x|P}(x is the general form of the elements of this set, and p is the * * * homology of the elements of this set). For example, a set of positive real numbers less than π is expressed as {x | 0.

3. Schema Method (venn diagram): In order to visually represent a set, we often draw a closed curve (or circle) and use its interior to represent a set.

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