Question

Ср даю 50 балов +5звезд и коронку

Answer 1

$\displaystyle\bf\\1)\\\\7x-5y=-1\\\\\Big(2 \ ; \ 3\Big) \ \ \ \Rightarrow \ \ \ x=2 \ \ ; \ \ y=3\\\\7\cdot 2-5\cdot 3=-1\\\\14-15=-1\\\\-1=-1 \ - \ verno\\\\Otvet \ : \ \Big(2 \ ; \ 3\Big)\\\\\\2)\\\\\left \{ {{7x-4y=-18} \atop {2y-3x=8} \ |\cdot 2} \right.\\\\\\+\left \{ {{7x-4y=-18} \atop {-6x+4y=16} } \right.\\----------\\x=-2\\\\2y=3x+8=3\cdot(-2)+8=-6+8=2\\\\y=1\\\\Otvet \ : \ \Big(-2 \ ; \ 1\Big)$