Question

помогите пожалуйста

Answer 1

x =y+16
xy=80
(y+16)*y=80
y2+16y-80=0
y=-20 или y=4
x=-4 или x=20

Answer 2

$\left \{ {{x-y=16} \atop {xy=80}} \right.\; \; \left \{ {x=y+16} \atop {(y+16)y=80}} \right.\; \; \left \{ {{x=y+16} \atop {y^2+16y-80=0}} \right. \; \; \left \{ {{x=y+16} \atop {y_1=-20\; ,\; y_2=4}} \right. \; \left \{ {{x_1=-4,\; x_2=20} \atop {y_1=-20,\; y_2=4}} \right. \\\\y^2+16y-80=0\; ,\\\\\frac{D}{4}=8^2+80=144\; ; \; \; y_1=-8-12=-20\; ,\; y_2=-8+12=4\\\\Otvet:\; \; (-4\, ;-20)\; ,\; \; (20\, ;4)\; .$