CHO A(0; 2; –2), B(–3; 1; –1), C(4; 3; 0), D(1; 2; M). TÌM M...

Câu 19. Cho A(0; 2; –2), B(–3; 1; –1), C(4; 3; 0), D(1; 2; m). Tìm m để A, B, C, D đồng phẳng: 18 A. –5. B. –1. C. 1. D. 5.