Решебник по математике 6 класс Виленкин Часть 1, 2 Часть 2. Параграф 5. Решение уравнений Задание 124

\[\boxed{\text{5.\ 124}}\]

\[\textbf{а)} - 5 \cdot ( - y + 9) = y + 10\]

\[5y - 45 = y + 10\]

\[5y - y = 10 + 45\]

\[4y = 45\]

\[y = 45\ :4\]

\[y = 11\frac{1}{4} = 11,25.\]

\[\textbf{б)}\ m - 17 = (m + 4) \cdot ( - 9)\]

\[m - 17 = - 9m - 36\]

\[m + 9m = - 36 + 17\]

\[10m = - 19\]

\[m = - 19\ :10\]

\[m = - 1,9.\]

\[\textbf{в)}\ 17 - 4 \cdot (m + 11) = 43\]

\[17 - 4m - 44 = 43\]

\[- 4m = 43 + 27\]

\[- 4m = 70\]

\[m = 70\ :( - 4) = - \frac{70}{4} = - \frac{35}{2}\]

\[m = - 17,5.\]

\[\textbf{г)} - 7 \cdot (4x + 2) - 3 = - 17\]

\[- 28x - 14 - 3 = - 17\]

\[- 28x = - 17 + 17\]

\[- 28x = 0\]

\[x = 0.\]

\[\textbf{д)} - 4,8y + 7,2 =\]

\[= 3 \cdot (2,4y + 4,8)\]

\[- 4,8y + 7,2 = 7,2y + 14,4\]

\[- 4,8y - 7,2y = 14,4 - 7,2\]

\[- 12y = 7,2\]

\[y = 7,2\ :( - 12)\]

\[y = - 0,6.\]

\[\textbf{е)} - 5 \cdot (0,6y - 1,8) =\]

\[= - 2y + 8,5\]

\[- 3y + 9 = - 2y + 8,5\]

\[- 3y + 2y = 8,5 - 9\]

\[- y = - 0,5\]

\[y = 0,5.\]