Question

Помогите, пожалуйста!!! Очень срочно
(решить системы ) ​

Answer 1

$\displaystyle\bf1)\\-\left \{ {{x^{2} +y^{2} =25} \atop {x^{2} +y=5}} \right. \\---------\\y^{2} -y=20\\\\y^{2} -y-20=0\\\\Teorema \ Vieta:\\\\y_{1} =5 \ \ ; \ \ y_{2} =-4\\\\1) \ x^{2} =5-y=5-5=0\\\\x=0\\\\2) \ x^{2} =5-y=5-(-4)=5+4=9\\\\x=\pm 3\\\\Otvet:(0 \ ; \ 5) \ , \ (-3 \ ; \ -4) \ , \ (3 \ ; \ -4)$

$\displaystyle\bf2)\\\left \{ {{y=x^{2} +4x} \atop {y=-2x+8}} \right. \\\\x^{2} +4x=-2x+8\\\\x^{2} +6x-8=0\\\\D=6^{2} -4\cdot(-8)=36+32=68=(2\sqrt{17} )^{2} \\\\x_{1} =\frac{-6-2\sqrt{17} }{2} =-3-\sqrt{17}\\\\\\x_{2} =\frac{-6+2\sqrt{17} }{2} =\sqrt{17} -3\\\\y_{1}=-2\cdot(-3-\sqrt{17} )+8=6+2\sqrt{17} +8=14+2\sqrt{17} \\\\y_{2}=-2\cdot(\sqrt{17}-3 )+8=6-2\sqrt{17} +8=14-2\sqrt{17} \\\\Otvet:(-3-\sqrt{17} \ ; \ 14+2\sqrt{17} ) \ , \ (\sqrt{17} -3 \ , \ 14-2\sqrt{17} )$