Question

Розв’яжіть систему рівнянь способом підстановки:
{2х-3(у+1)=-2
3(х+1)+3у=2у-1

Answer 1

$\displaystyle\bf\\\left \{ {{2x-3(y+1)=-2} \atop {3(x+1)+3y=2y-1}} \right. \\\\\\\left \{ {{2x-3y-3=-2} \atop {3x+3+3y=2y-1}} \right. \\\\\\\left \{ {{2x-3y=-2+3} \atop {3x+3y-2y=-1-3}} \right. \\\\\\\left \{ {{2x-3y=1} \atop {3x+y=-4}} \right. \\\\\\\left \{ {{y=-3x-4} \atop {2x-3\cdot(-3x-4)=1}} \right. \\\\\\\left \{ {{y=-3x-4} \atop {2x+9x+12=1}} \right. \\\\\\\left \{ {{y=-3x-4} \atop {11x=-11}} \right. \\\\\\\left \{ {{x=-1} \atop {y=-3\cdot(-1)-4}} \right.$

$\displaystyle\bf\\\left \{ {{x=-1} \atop {y=3-4}} \right. \\\\\\\left \{ {{x=-1} \atop {y=-1}} \right. \\\\\\Otvet \ : \ (-1 \ ; \ -1)$