\begin{matrix} \to a \circ (\to b + \to c) = a_{1} \circ (b_{1} + c_{1}) + a_{2} \circ (b_{2} + c_{2}) = (a_{1} \cdot b_{1} + a_{1} \cdot c_{1}) + (a_{2} \cdot b_{2} + a_{2} \cdot c_{2}) = \to a \circ \to b + \to a \circ \to c \end{matrix}

${\begin {array} {l} \vec a \circ (\vec b + \vec c) = a_1 \circ (b_1 + c_1) + a_2 \circ (b_2 + c_2) \\ = (a_1 \cdot b_1 + a_1 \cdot c_1) + (a_2 \cdot b_2 + a_2 \cdot c_2) \\ = \vec a \circ \vec b + \vec a \circ \vec c \end {array}}$

\begin{matrix} \to a \circ (\to b + \to c) = a_{1} \circ (b_{1} + c_{1}) + a_{2} \circ (b_{2} + c_{2}) = (a_{1} \cdot b_{1} + a_{1} \cdot c_{1}) + (a_{2} \cdot b_{2} + a_{2} \cdot c_{2}) = \to a \circ \to b + \to a \circ \to c \end{matrix}

$\begin {array} {l} \vec a \circ (\vec b + \vec c) = a_1 \circ (b_1 + c_1) + a_2 \circ (b_2 + c_2) \\ = (a_1 \cdot b_1 + a_1 \cdot c_1) + (a_2 \cdot b_2 + a_2 \cdot c_2) \\ = \vec a \circ \vec b + \vec a \circ \vec c \end {array}$

\begin {array} {l} \vec a \circ {\vec b + \vec c}

$\begin {array} {l} \vec a \circ {\vec b + \vec c}$

a

$a$

Lisa