Answer:
[tex]y=-4x+17[/tex]
Step-by-step explanation:
[tex]\begin{pmatrix}4&1\end{pmatrix}\quad \mathrm{and}\quad \begin{pmatrix}2&9\end{pmatrix}[/tex]
[tex]\mathrm{Computing\:dot\:product\:of\:two\:vectors}:\quad \left(x_1,\:\:\ldots ,\:\:x_n\right)\cdot \left(y,\:\:\ldots ,\:\:y_n\right)=\sum _{i=1}^nx_iy_i[/tex]
[tex]=4\cdot \:2+1\cdot \:9[/tex]
[tex]=17[/tex]
