Question

ПОМОГИТЕ СРОЧНО ОЧЕНЬ ПРОШУ МЕТОДОМ 9 КЛАСС!!!!!! ДАЮ 40 БАЛОВ!!!!!!!!!!!!

Answer 1

Ответ: ( 4 ; 2 ) и ( -4 ; -2 )

Объяснение:

$\left \{ \begin{array}{l} xy -\dfrac{x}{y} = 6 \\\\ 3xy + \dfrac{2x}{y} = 28 \end{array} \right. \\\\\\ Zamena :\\\\ xy = a \\\\ \dfrac{x}{ y} = b \\ ------------ \\\\\ \oplus \left \{ \begin{array}{l} a-b = 6 ~~ \big | \cdot 2 \\\\ 3a+2b = 28 \end{array} \right. \Leftrightarrow \oplus \left \{ \begin{array}{l} 2a-2b = 12 \\\\ 3a+2b = 28 \end{array} \right. \Leftrightarrow \\\\\\\ 3a+2a +2b- 2b = 12+ 28 \\\\ 5a = 40 \\\\ a = 8 \\\\ b = a-6 = 2$

$\left \{ \begin{array}{l} xy = 8 \\\\ \dfrac{x}{y} =2 \end{array} \right. \Leftrightarrow \left \{ \begin{array}{l} xy = 8 \\\\ x =2y ~ ; ~ y \neq 0 \end{array} \right. \Leftrightarrow \\\\\\ 2y\cdot y = 8 \\\\\ y ^2 = 4 \\\\ y _{1;2} = \pm 2 \\\\ x_{1;2 } = \pm 4$