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Use descriptive method to represent the following set: 1. Set composed of a city in Beijing; 2. Set of all even numbers
Express with description
1. A collection of one city in Beijing
Set a = {x | x = Beijing}
2. The set of all even numbers
Set a = {x | x = 2n, n ∈ n +} (note which + sign is in the lower right corner)
The following set (1) is composed of a city in Shanghai, and (2) is composed of even numbers
This one
The set of all odd numbers is represented by description
{x | x=2k+1,k∈Z}
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