ГДЗ по алгебре 7 класс Макарычев Задание 132

\[\boxed{\text{132\ (132).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[\textbf{а)}\ (13x - 15) - (9 + 6x) = - 3x\]

\[13x - 15 - 9 - 6x + 3x = 0\]

\[10x - 24 = 0\]

\[10x = 24\]

\[x = 24\ :10\]

\[x = 2,4\]

\[Ответ:x = 2,4.\]

\[\textbf{б)}\ 12 - (4x - 18) =\]

\[= (36 + 4x) + (18 - 6x)\]

\[12 - 4x + 18 =\]

\[= 36 + 4x + 18 - 6x\]

\[30 - 4x = 54 - 2x\]

\[- 4x + 2x = 54 - 30\]

\[- 2x = 24\]

\[x = 24\ :( - 2)\]

\[x = - 12\]

\[Ответ:x = - 12.\]

\[\textbf{в)}\ 1,6x - (x - 2,8) =\]

\[= (0,2x + 1,5) - 0,7\]

\[1,6x - x + 2,8 =\]

\[= 0,2x + 1,5 - 0,7\]

\[0,6x + 2,8 = 0,2x + 0,8\]

\[0,6x - 0,2x = 0,8 - 2,8\]

\[0,4x = - 2\]

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

\[x = - 20\ :4\]

\[x = - 5\]

\[Ответ:x = - 5.\]

\[\textbf{г)}\ (0,5x + 1,2) - (3,6 - 4,5x) =\]

\[= (4,8 - 0,3x) + (10,5x + 0,6)\]

\[0,5x + 1,2 - 3,6 + 4,5x =\]

\[= 4,8 - 0,3x + 10,5x + 0,6\]

\[5x - 2,4 = 10,2x + 5,4\]

\[5x - 10,2x = 5,4 + 2,4\]

\[- 5,2x = 7,8\]

\[x = 7,8\ :( - 5,2)\]

\[x = - 78\ :52\]

\[x = - \frac{78}{52} = - \frac{39}{26} = - \frac{3}{2}\]

\[x = - 1,5\]

\[Ответ:x = - 1,5.\]