Question

Розв'яжіть систему рівняння {3х+у=0 {у-х=1

Answer 1

$\displaystyle\bf\\\left \{ {{3x+y=0} \atop {y-x=1}} \right. \\\\\\\left \{ {{y=-3x} \atop {-3x-x=1}} \right. \\\\\\\left \{ {{y=-3x} \atop {-4x=1}} \right. \\\\\\\left \{ {{x=-0,25} \atop {y=-3\cdot(-0,25)}} \right. \\\\\\\left \{ {{x=-0,25} \atop {y=0,75}} \right. \\\\\\Otvet: \ \Big(-0,25 \ \ ; \ \ 0,75\Big)$