벡터의 성분 연산

문제

두 벡터 $\vec{a} = (2, -1)$과 $\vec{b} = (3, 4)$에 대하여 벡터 $2\vec{a} - \vec{b}$의 성분은?

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<!-- x-values from -9 to 9, SVG x from 20 to 380 -->
<line x1="20" y1="20" x2="20" y2="290"/>
<line x1="40" y1="20" x2="40" y2="290"/>
<line x1="60" y1="20" x2="60" y2="290"/>
<line x1="80" y1="20" x2="80" y2="290"/>
<line x1="100" y1="20" x2="100" y2="290"/>
<line x1="120" y1="20" x2="120" y2="290"/>
<line x1="140" y1="20" x2="140" y2="290"/>
<line x1="160" y1="20" x2="160" y2="290"/>
<line x1="180" y1="20" x2="180" y2="290"/>
<line x1="220" y1="20" x2="220" y2="290"/>
<line x1="240" y1="20" x2="240" y2="290"/>
<line x1="260" y1="20" x2="260" y2="290"/>
<line x1="280" y1="20" x2="280" y2="290"/>
<line x1="300" y1="20" x2="300" y2="290"/>
<line x1="320" y1="20" x2="320" y2="290"/>
<line x1="340" y1="20" x2="340" y2="290"/>
<line x1="360" y1="20" x2="360" y2="290"/>
<line x1="380" y1="20" x2="380" y2="290"/>

O 2 4 -2 2 4 -2 -4 -6 a b 2a -b 2a - b