... k(5 - y) y = -7 7 - z = k(-2 - z) z = 16G(4DCBAxxxx +++,4DCBAyyyy +++,4DCBAzzzz +++ ) Bi 9 (Trang 6 7): A(1, 3, 1), B(0, 1, 2), C(0, 0, 1) AB= (-1, -2, 1) AC = (-1, -3, 0) ⇒ ... 4; - 6) Bi 12 (Trang 6 7): A = (2, -1, 7); B = (4, 5, - 2), AB = (2, 6, - 9) AB càõt Oyz tải M(0, y, z). Ta cọ MA= kMB⇒ 2 = 4k ⇒ k = 1/2 -1 - y = k(5 - y) y = -7 7 - z = k(-2 - z) z = ... (Trang 7 5) a = (1, -1, 1); b = (4, 0, - 1), c = (3, 2, - 1) nãn:a, (a.b ) c = (9, 6, - 3); b, a2(b.c ) = 39; c, a2b+cb2 + c2a= (77, 20, - 6) .…Bi 2 (Trang 7 5) a,Tênh...