1. **State the problem:** Given vectors $a = \begin{pmatrix} -2 \\ 3 \end{pmatrix}$ and $b = \begin{pmatrix} 5 \\ -1 \end{pmatrix}$, find the column vectors for:
(i) $a + b$
(ii) $2a - b$
2. **Recall vector addition and scalar multiplication:**
- To add vectors, add their corresponding components.
- To multiply a vector by a scalar, multiply each component by that scalar.
3. **Calculate (i) $a + b$:**
$$a + b = \begin{pmatrix} -2 \\ 3 \end{pmatrix} + \begin{pmatrix} 5 \\ -1 \end{pmatrix} = \begin{pmatrix} -2 + 5 \\ 3 + (-1) \end{pmatrix} = \begin{pmatrix} 3 \\ 2 \end{pmatrix}$$
4. **Calculate (ii) $2a - b$:**
First, calculate $2a$:
$$2a = 2 \times \begin{pmatrix} -2 \\ 3 \end{pmatrix} = \begin{pmatrix} 2 \times -2 \\ 2 \times 3 \end{pmatrix} = \begin{pmatrix} -4 \\ 6 \end{pmatrix}$$
Then subtract $b$:
$$2a - b = \begin{pmatrix} -4 \\ 6 \end{pmatrix} - \begin{pmatrix} 5 \\ -1 \end{pmatrix} = \begin{pmatrix} -4 - 5 \\ 6 - (-1) \end{pmatrix} = \begin{pmatrix} -9 \\ 7 \end{pmatrix}$$
**Final answers:**
(i) $a + b = \begin{pmatrix} 3 \\ 2 \end{pmatrix}$
(ii) $2a - b = \begin{pmatrix} -9 \\ 7 \end{pmatrix}$
Vector Operations 4E42Dc
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