Answer
See below.
Work Step by Step
$z=5$, thus plugging this into the second equation: $y+2\cdot5=13\\y+10=13\\y=3$
Thus plugging these values into the first equation: $x+3+2\cdot5=19\\x+13=19\\x=6$
It is easy to solve it because we can start from the bottom plug the values in and get easily solvable equations.
