Let ${\bf a}_1 = \left[{\begin{matrix}-4 \cr -3 \cr \end{matrix}}\right]$, ${\bf a}_2 = \left[{\begin{matrix}-16 \cr -15 \cr \end{matrix}}\right]$, and ${\bf b} = \left[{\begin{matrix}40 \cr 39 \cr \end{matrix}}\right]$.

Is ${\bf b}$ a linear combination of ${\bf a}_1$ and ${\bf a}_2$?
A. Yes ${\bf b}$ is a linear combination.
B. ${\bf b}$ is not a linear combination.
C. We cannot tell if ${\bf b}$ is a linear combination.

Either fill in the coefficients of the vector equation, or enter "NONE" if no solution is possible.

${\bf b}=$ ${\bf a}_1+$ ${\bf a}_2$