Test video

Which of the following correctly represents the set of natural numbers?

• {1; 2; 3; ...}

• {0; 1; 2; 3; ...}

• {..., -2; -1; 0; 1; 2; ...}

• {0; 2; 4; 6; ...}

What is the set of natural numbers excluding zero?

• {0; 1; 2; 3; ...}

• {..., -2; -1; 0; 1; 2; ...}

• {1; 2; 3; ...}

• {0; 2; 4; 6; ...}

Tính 3 + 4 =

• 6

• 7

• 8

• 9

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Which of the following correctly represents the set B = {0; 2; 4; 6; 8} using characteristic properties?

• {x ∈ N | x is an even number, x < 9}

• {x ∈ N* | x is an even number, x < 9}

• {x ∈ N | x is an even number, x < 8}

• {x ∈ N | x is an even number, x > 0, x < 9}

How should the number 123456789 be written for easy readability, according to the standard convention?

• 123456789

• 123 456 789

• 12 345 6789

• 1 234 567 89