Question

[Pham Trong Bach]

Trong không gian Oxy cho ba vecto  $\stackrel{\rightharpoonup }{a}=\left(2;-5;3\right)$; $\stackrel{\rightharpoonup }{b}=\left(0;2;-1\right)$; $\stackrel{\rightharpoonup }{c}=\left(1;7;2\right)$. Tọa độ của vecto  $\stackrel{\rightharpoonup }{u}=4\stackrel{\rightharpoonup }{a}-\frac{\stackrel{\rightharpoonup }{b}}{3}+3\stackrel{\rightharpoonup }{c}$, là:

A.  $\stackrel{\rightharpoonup }{u}=\left(11;\frac{1}{3};\frac{55}{3}\right)$

B.  $\stackrel{\rightharpoonup }{u}=\left(-11;\frac{1}{3};\frac{55}{3}\right)$

C.  $\stackrel{\rightharpoonup }{u}=\left(11;\frac{-1}{3};\frac{55}{3}\right)$

D.  $\stackrel{\rightharpoonup }{u}=\left(11;\frac{-1}{3};\frac{-55}{3}\right)$

Answer 1

[Cao Minh Tâm]

Đáp án đúng : A