Incorrect. Multiply the first equation by 5 and the second equation by 2:

$\displaystyle{35}{x}-{10}{y}=-{155}\usepackage{cmbright}\Huge\$

$\displaystyle{12}{x}+{10}{y}={14}\usepackage{cmbright}\Huge\$

Add the equations to eliminate y, and then solve for x. Substitute the result back into one of the equations and solve for y.