Consider the following system of equations.

$\displaystyle-{x}+{2}{y}+{2}{z}=-{1}\usepackage{cmbright}\Huge\$

$\displaystyle{2}{x}-{y}-{z}={5}\usepackage{cmbright}\Huge\$

$\displaystyle{3}{x}+{y}-{2}{z}={10}\usepackage{cmbright}\Huge\$

Which of the following procedures will successfully eliminate the variable $\displaystyle{y}\usepackage{cmbright}\Huge\$ ?