ГДЗ по алгебре 7 класс Макарычев Задание 605

\[\boxed{\text{605\ (605).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[\textbf{а)}\ (23 + 3x) + (8x - 41) = 15\]

\[23 + 3x + 8x - 41 = 15\]

\[11x = 15 + 18\]

\[11x = 33\]

\[x = 33\ :11\]

\[x = 3\]

\[Ответ:x = 3.\]

\[\textbf{б)}\ (19 + 2x) - (5x - 11) = 25\]

\[19 + 2x - 5x + 11 = 25\]

\[- 3x = 25 - 30\]

\[- 3x = - 5\]

\[x = \frac{5}{3}\]

\[x = 1\frac{2}{3}\]

\[Ответ:x = 1\frac{2}{3}.\]

\[\textbf{в)}\ (3,2y - 1,8) - (5,2y + 3,4) =\]

\[= - 5,8\]

\[3,2y - 1,8 - 5,2y - 3,4 = - 5,8\]

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

\[- 2y = - 0,6\]

\[y = - 0,6\ :( - 2) = 6\ :20\]

\[y = 0,3\]

\[Ответ:y = 0,3.\]

\[\textbf{г)}\ 1 - (0,5x - 15,8) =\]

\[= 12,8 - 0,7x\]

\[1 - 0,5x + 15,8 + 0,7x = 12,8\]

\[0,2x = 12,8 - 16,8\]

\[0,2x = - 4\]

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

\[x = - 20\]

\[Ответ:x = - 20.\]

\[\textbf{д)}\ 3,8 - 1,5y + (4,5y - 0,8) =\]

\[= 2,4y + 3\]

\[3,8 - 1,5y + 4,5y - 0,8 - 2,4y =\]

\[= 3\]

\[0,6y = 3 - 3\]

\[0,6y = 0\]

\[y = 0\]

\[Ответ:y = 0.\]

\[\textbf{е)}\ 4,2y + 0,8 =\]

\[= 6,2y - (1,1y + 0,8) + 1,2\]

\[4,2y + 0,8 =\]

\[= 6,2y - 1,1y - 0,8 + 1,2\]

\[4,2y - 5,1y = 0,4 - 0,8\]

\[- 0,9y = - 0,4\]

\[9y = 4\]

\[y = \frac{4}{9}\]

\[Ответ:y = \frac{4}{9}.\]