Решебник по математике 6 класс Мерзляк ФГОС Задание 1154

 

\[\boxed{\mathbf{1154\ (1146)}\mathbf{.}\mathbf{\ }Еуроки\ - \ ДЗ\ без\ мороки}\]

\[1)\ 9 \cdot (x - 1) = x + 15\]

\[9x - 9 = x + 15\]

\[9x - x = 15 + 9\]

\[8x = 24\]

\[x = 3\]

\[Ответ:3.\]

\[2)\ (11x + 14) - (5x - 8) = 25\]

\[11x + 14 - 5x + 8 = 25\]

\[6x = 25 - 14 - 8\]

\[6x = 3\]

\[x = 0,5\]

\[Ответ:0,5.\]

\[3)\ 12 - 4 \cdot (x - 3) = 39 - 9x\]

\[12 - 4x + 12 = 39 - 9x\]

\[- 4x + 9x = 39 - 12 - 12\]

\[5x = 15\]

\[x = 3\]

\[Ответ:3.\]

\[4)\ 2 \cdot (3x + 5) -\]

\[- 3 \cdot (4x - 1) = 11,8\]

\[6x + 10 - 12x + 3 = 11,8\]

\[- 6x = 11,8 - 10 - 3\]

\[- 6x = - 1,2\]

\[x = 0,2\]

\[Ответ:0,2.\]