Question

помогите решить дам 70 баллов​

Answer 1

Ответ:

$1.$

$\left \{ {{x^2-y^2=5} \atop {x+y=-1}} \right. \Rightarrow\left \{ {{x^2-y^2=5} \atop {x=-1-y}} \right. \Rightarrow(-1-y)^2-y^2=5\Rightarrow1+2y+y^2-y^2=5\Rightarrow1+2y=5\\\\\Rightarrow 2y=4 \Rightarrow y=2\Rightarrow\left \{ {{x^2-2^2=5} \atop {x+2=-1}} \right. \Rightarrow\left \{ {{x=-3} \atop {y=2}} \right.$

$\\\left \{ {{x-y=1} \atop {xy=6}} \right. \Rightarrow\left \{ {{x=1+y} \atop {xy=6}} \right. \Rightarrow(1+y)\times y=6\Rightarrow y+y^2=6 \Rightarrow y+y^2-6=0 \Rightarrow y^2+3y-2y-6=0 \Rightarrow y\times(y+3)-2\times(y+3)=0\Rightarrow(y+3)\times(y-2)=0\Rightarrow y_1=-3\,\,\,,y_2=2\Rightarrow\left \{ {{x_1=2} \atop {y_1=-3}} \right. ,\left \{ {{x_2=-3} \atop {y_2=2}} \right.$

$2.$

Не знаю сорри