Question

Розв’яжіть систему рівнянь способом підстановки:
1) {3х+у=1
2х-3у=-14

Answer 1

$\displaystyle\bf\\\left \{ {{3x+y=1} \atop {2x-3y=-14}} \right. \\\\\\\left \{ {{y=1-3x} \atop {2x-3\cdot(1-3x)=-14}} \right. \\\\\\\left \{ {{y=1-3x} \atop {2x-3+9x=-14}} \right. \\\\\\\left \{ {{y=1-3x} \atop {11x=-11}} \right. \\\\\\\left \{ {{x=-1} \atop {y=1-3\cdot(-1)}} \right. \\\\\\\left \{ {{x=-1} \atop {y=1+3}} \right. \\\\\\\left \{ {{x=-1} \atop {y=4}} \right. \\\\\\Otvet \ : \ (-1 \ ; \ 4)$