Linear algebra problem: How to read this line notation?

Question

I've come across something I haven't seen before. I was wondering how one reads this notation of a line: $$m:\begin{bmatrix}15\\12\end{bmatrix}\begin{bmatrix}x\\y\end{bmatrix}=\begin{bmatrix}15\\12\end{bmatrix}\begin{bmatrix}6\\-\frac{91}{12}\end{bmatrix}$$

Answer 1

One way to make sense of this is to write $$\begin{bmatrix} 15 & 12 \end{bmatrix} \begin{bmatrix} x\\y \end{bmatrix} = \begin{bmatrix} 15 & 12 \end{bmatrix} \begin{bmatrix} 6\\-\frac{91}{12} \end{bmatrix}.$$ This can be written $15x + 12y = 15(6) + 12 (-\frac{91}{12})$.