Question

[Quỳnh Anh]

Cho hình hộp ABCD.A'B'C'D', đặt \(\overrightarrow{AB}=\overrightarrow{a},\overrightarrow{AD}=\overrightarrow{b},\overrightarrow{AA'}=\overrightarrow{c},\) thì đẳng thức nào sau đây đúng?

A. \(\overrightarrow{BD'}=-\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c}\)

B. \(\overrightarrow{BD'}=\overrightarrow{a}-\overrightarrow{b}-\overrightarrow{c}\)

C. \(\overrightarrow{BD'}=\overrightarrow{a}+\overrightarrow{b}-\overrightarrow{c}\)

D. \(\overrightarrow{BD'}=\overrightarrow{a}-\overrightarrow{b}+\overrightarrow{c}\)

Answer 1

[Nguyễn Việt Lâm]

\(\overrightarrow{BD'}=\overrightarrow{BA}+\overrightarrow{AD}+\overrightarrow{DD'}=-\overrightarrow{AB}+\overrightarrow{AD}+\overrightarrow{AA'}\)

\(=-\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c}\)