Question

Помоготе сделать номер 8.

Answer 1

Объяснение:

$\left \{ {{x=4+y} \atop {\frac{1}{y}-\frac{1}{4+y}=\frac{4}{5} }} \right. \\\\\left \{ {{x=4+y} \atop {\frac{4+y}{y(4+y)}-\frac{y}{y(4+y)} = \frac{4}{5} }} \right. \\\left \{ {{x=4+y} \atop {\frac{4+y-y}{4y + y^{2} }= \frac{4}{5} }} \right.\\\\\left \{ {{x=4+y} \atop {\frac{4}{4y+y^{2} } } =\frac{4}{5}} \right. \\\\\left \{ {{x=4+y} \atop {4y+y^{2} =5}} \right. , y \neq 0\\\left \{ {{x=4+y} \atop {y^{2}+4y - 5 = 0 }} \right.$$\left \{ {{x = 4+ y} \atop {y_{1} = -5, y_{2} = 1}} \right. \\\\\left \{ {{x_{1}= -1, x_{2} =5 } \atop {y_{1} = -5, y_{2} = 1}} \right. \\Otvet: (-1;-5) (5;1)$