помогите, пожалуйста, решить систему: 2x+2y=x-1 3y-x=4-y

$\left \{ {2x + 2y = x -1} \atop {3y - x = 4 - y}} \right.\\\\ \left \{ {x + 2y = -1} \atop {4y - x = 4 \ | * -1}} \right.\\\\ \left \{ {x + 2y = -1} \atop {-4y + x = -4}} \right.$

$\left \{ {x + 2y = -1} \atop {x = -4 + 4y}} \right.\\\\ \left \{ {-4 + 4y + 2y = -1} \atop {x = -4 + 4y}} \right.\\\\ \left \{ {6y = 3} \atop {x = -4 + 4y}} \right.\\\\ \left \{ {y = \frac{3}{6}} \atop {x = 4 + 4(\frac{3}{6})}} \right.\\\\\ \left \{ {y = \frac{1}{2}} \atop {x = -4 + 2}} \right.\\\\ \left \{ {y = \frac{1}{2}} \atop {x = -2}} \right.$