ГДЗ по алгебре 7 класс Макарычев Задание 360

\[\boxed{\text{360\ (360).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[если\ x = - 25:\]

\[y = 0,2 \cdot ( - 25) - 4 = - 5 - 4 = - 9;\]

\[если\ x = - 12:\]

\[y = 0,2 \cdot ( - 12) - 4 = - 2,4 - 4 = - 6,4;\]

\[если\ x = 45:\]

\[y = 0,2 \cdot 45 - 4 = 9 - 4 = 5;\]

\[если\ x = 60:\]

\[y = 0,2 \cdot 60 - 4 = 12 - 4 = 8.\]

\[0 = 0,2x - 4\]

\[0,2x = 4\ \ \]

\[x = 4\ :0,2 = 40\ :2\]

\[x = 20.\]

\[1 = 0,2x - 4\]

\[0,2x = 4 + 1\]

\[0,2x = 5\ \ \]

\[x = 5\ :0,2 = 50\ :2\]

\[x = 25.\]

\[\textbf{а)}\ y = x:\]

\[x = 0,2x - 4\]

\[0,8x = - 4\]

\[x = - 5 \Longrightarrow \ \ y = x = - 5;\]

\[Да,\ существует:\]

\[x = y = - 5.\]

\[\textbf{б)}\ y = - x:\]

\[- x = 0,2x - 4\]

\[- 1,2x = - 4\]

\[x = \frac{4}{1,2} = \frac{1}{0,3} = \frac{10}{3} = 3\frac{1}{3}\]

\[Да,\ существует:\]

\[x = 3\frac{1}{3};\ \ y = - 3\frac{1}{3}.\]