Question

[trần trang]

Tìm tất cả các tập hợp X sao cho:

a) \(\left\{1,2\right\}\subset X\subset\left\{1,2,3,4,5\right\}.\)

b) \(\left\{1,2\right\}\cup X=\left\{1,2,3,4\right\}.\)

Answer 1

[Hoàng Tử Hà]

a/ \(\left\{1;2\right\};\left\{1;2;3\right\};\left\{1;2;4\right\};\left\{1;2;5\right\};\left\{1;2;3;4;5\right\}\)

b/ \(\left\{1;2;3;4\right\}\)