Question

What does y equal? ​

Answer 1

`y=-4x+17`

Explanation:

`\begin{pmatrix}4&1\end{pmatrix}\quad \mathrm{and}\quad \begin{pmatrix}2&9\end{pmatrix}`

`\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`

`=4\cdot \:2+1\cdot \:9`

`=17`