Question

во 2 сколько решений имеет система​

Answer 1

Ответ:

2

Объяснение:

x=8/y

y=4(8/y)

x=8/y

y=32/4y

x=8/y

4y^2=32

y^2=8

x=8/y

Одинаковый квадрат имеют противоположные числа => Уравнение имеет 2 решения

Answer 2

$\displaystyle\bf\\\left \{ {{y=\dfrac{8}{x} } \atop {y=4x}} \right. \\\\\\\frac{8}{x} =4x\\\\\\4x^{2} =8\\\\\\x^{2} =2\\\\\\x_{1} =-\sqrt{2} \ \ \ ; \ \ \ x_{2} =\sqrt{2} \\\\\\y_{1} =-4\sqrt{2} \ \ ; \ \ y_{2} =4\sqrt{2} \\\\\\Otvet: \ \Big(-\sqrt{2} \ ; \ -4\sqrt{2} \Big) \ \ ; \ \ \Big(\sqrt{2} \ ; \ 4\sqrt{2} \Big)$

Система имеет два решения

$\displaystyle\bf\\1)\\\\\left \{ {{x-y=7} \atop {xy=-10}} \right. \\\\\\\left \{ {{x=y+7} \atop {(y+7)\cdot y=-10}} \right.\\\\\\\left \{ {{x=y+7} \atop {y^{2} +7y+10=0}} \right. \\\\\\\left \{ {{x=y+7} \atop {\left[\begin{array}{ccc}y_{1} =-2\\y_{2} =-5\end{array}\right}} \right. \\\\\\\left[\begin{array}{ccc}\left \{ {{x_{1} =-2+7} \atop {y_{1} =-2}} \right. \\\left \{ {{x_{2} =-5+7} \atop {y_{2} =-5}} \right. \end{array}\right$

$\displaystyle\bf\\\left[\begin{array}{ccc}\left \{ {{x_{1} =5} \atop {y_{1} =-2}} \right. \\\left \{ {{x_{2} =2} \atop {y_{2} =-5}} \right. \end{array}\right\\\\\\Otvet: \ (5 \ ; \ -2) \ , \ (2 \ ; \ -5)$