Question

7x+3y=-1 3x-6=19 система уравнений способом сложения

Answer 1

$\displaystyle\bf\\\left \{ {{7x+3y=-1} \ |\cdot 2\atop {3x-6y=19}} \right. \\\\\\+\left \{ {{14x+6y=-2} \atop {3x-6y=19}} \right.\\----------\\17x=17\\\\x=1\\\\3y=-7x-1=-7\cdot 1 - 1=-8\\\\y=-8:3=-2\frac{2}{3} \\\\Otvet: \ \Big(1 \ ; \ -2\frac{2}{3} \Big)$