Solve for the unknowns in the vector equation below.

$2 \left[\begin{matrix} 2 \cr a \cr \end{matrix}\right] - 5 \left[\begin{matrix} 5 \cr 9 \cr \end{matrix}\right] +5 \left[\begin{matrix} b \cr -2 \cr \end{matrix}\right] = \left[\begin{matrix} 4 \cr 8 \cr \end{matrix}\right]$

$a=$

$b=$