Correct. Substitute $\displaystyle{1}-{x}\usepackage{cmbright}\Huge\$ for y in the first equation: $\displaystyle{2}{x}-{5}{\left({1}-{x}\right)}=-{26}\usepackage{cmbright}\Huge\$

Simplify and solve for x: $\displaystyle{2}{x}-{5}+{5}{x}=-{26}\usepackage{cmbright}\Huge\$ , $\displaystyle{7}{x}-{5}=-{26}\usepackage{cmbright}\Huge\$ , $\displaystyle{7}{x}=-{21}\usepackage{cmbright}\Huge\$ , $\displaystyle{x}=-{3}\usepackage{cmbright}\Huge\$

Substitute this value for x back into the second equation: $\displaystyle{y}={1}-{\left(-{3}\right)}={1}+{3}={4}\usepackage{cmbright}\Huge\$