Answer:
A
Step-by-step explanation:
Matrix notation can be confusing, but it's important to remember that systems of equations are typically written as follows:
#x + #y + #z = #
so if there was only one equation it would be written like this:
[tex]\left[\begin{array}{ccc}5&2&1\end{array}\right] \left[\begin{array}{ccc}x\\y\\z\end{array}\right] = [16]\\\\5x + 2y + z = 16\\[/tex]
Then just follow the same pattern for the remaining equations
