Cho hệ các vector U = {(1,2,5 ); (0, -1, -4);(2, 3, 6); (1, 0, -3} .

a. Tìm số chiều và một cơ sở W của không gian con sinh bởi hệ vector U .

b. Tìm tham số k để 2

u k = + (2,3, 1) là một tổ hợp tuyến tính của W , và suy ra [ ]W

u .

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