Question

Cho \(\overrightarrow{a}=\left(1;-2\right);\overrightarrow{b}=\left(0;3\right)\)

Tìm tọa độ của các vectơ : \(\overrightarrow{x}=\overrightarrow{a}+\overrightarrow{b};\overrightarrow{y}=\overrightarrow{a}-\overrightarrow{b};\overrightarrow{z}=3\overrightarrow{a}-4\overrightarrow{b}\) ?

 

Answer 1

\(\overrightarrow{x}=\overrightarrow{a}+\overrightarrow{b}=\left(1+0;-2+3\right)=\left(1;1\right)\).
\(\overrightarrow{y}=\overrightarrow{a}-\overrightarrow{b}=\left(0-1;3-\left(-2\right)\right)=\left(-1;5\right)\).
\(\overrightarrow{z}=3\overrightarrow{a}-4\overrightarrow{b}=3\left(1;-2\right)-4\left(0;3\right)=\left(3;-6\right)-\left(0;12\right)\)\(=\left(3;-18\right)\).

Answer 2

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