Question

Много так-то.

Задания в скринах.

Answer 1

$1)\left \{ {{5x+3y=-1} \atop {-2x+5y=19}} \right.\\\\\left \{ {5x+3y=-1} \atop {5y=2x+19}} \right.\\\\\left \{ {{y=0,4x+3,8} \atop {5x+3*(0,4x+3,8)=-1}} \right.\\\\\left \{ {{y=0,4x+3,8} \atop {5x+1,2x+11,4=-1}} \right.\\\\\left \{ {{y=0,4x+3,8} \atop {6,2x=-12,4}} \right.\\\\\left \{ {{x=-2} \atop {y=0,4*(-2)+3,8}} \right.\\\\\left \{ {{x=-2} \atop {y=3}} \right.\\\\Otvet:\boxed{(-2;3)}$

$2)\left \{ {{4x-5y=-2}|*2 \atop {3x+2y=-13}|*5} \right. \\\\+\left \{ {{8x-10y=-4} \atop {15x+10y=-65}} \right. \\--------\\23x=-69\\\\x=-3\\\\2y=-13-3x=-13-3*(-3)=-13+9=-4\\\\y=-2\\\\Otvet:\boxed{(-3;-2)}$

$3)\left \{ {{\frac{x}{3}-\frac{y}{4}=3} \atop {(x-10)(y+2)=xy-70}} \right.\\\\\left \{ {{\frac{x}{3}*12-\frac{y}{4}*12=3*12} \atop {xy+2x-10y-20=xy-70}} \right.\\\\\left \{ {{4x-3y=36} \atop {2x-10y=-50}|*(-2)} \right.\\\\+\left \{ {{4x-3y=36} \atop {-4x+20y=100}} \right.\\ --------\\17y=136\\\\y=8\\\\x-5y=-25\\\\x=5y-25=5*8-25=40-25=15\\\\Otvet:\boxed{(15;8)}$

Answer 2

ответ:
1) (-2; 3)
2) (-3;-2)
3) (-15:-8)
кажется так