\begin{align*} \color{blue}\mathbf{u}~ &\color{blue}= \langle -1,~~~2,~~~4 \rangle \\ \color{red}\mathbf{v}~ &\color{red}= \langle ~~~2,~~~3,~~~2 \rangle \\ \\ \color{black}\mathbf{u}\cdot\mathbf{v}~ &\color{black}= u_1v_1 + u_2v_2 + u_3v_3 \\ &\color{black}= \color{blue}(-1)\color{red}(2) + \color{blue}(2)\color{red}(3) + \color{blue}(4)\color{red}(2) \\ &\color{black}= \boxed{12} \end{align*}
$\color{blue}\mathbf{u} \color{black}= \langle$ , , $\rangle$
$\color{red}\mathbf{v} \color{black}= \langle$ , , $\rangle$