Решебник по математике 6 класс Виленкин Часть 1, 2 Часть 1. Параграф 2. Действия со смешанными числами Задание 326

\[\boxed{\mathbf{2.}\mathbf{326}}\]

\[\textbf{а)}\ 11,4b - (2,7b + 3,2b) + 2,35 =\]

\[= 6,2\]

\[11,4b - 5,9b = 6,2 - 2,35\]

\[5,5b = 3,85\]

\[b = 3,85\ :5,5 = 385\ :550\]

\[b = 0,7.\]

\[\textbf{б)}\ 15d - (12,1d - 0,7d) + 5,6 =\]

\[= 20\]

\[15d - 11,4d = 20 - 5,6\]

\[3,6d = 14,4\]

\[d = 14,4\ :3,6 = 144\ :36\]

\[d = 4.\]

\[\textbf{в)}\ 3x + \frac{1}{6} - \left( 3\frac{1}{2}x - 1\frac{1}{4}x \right) =\]

\[= 4\frac{2}{3}\ \]

\[3x - \left( 3\frac{2}{4}x - 1\frac{1}{4}x \right) = 4\frac{2}{3} - \frac{1}{6}\]

\[3x - 2\frac{1}{4}x = 4\frac{4}{6} - \frac{1}{6}\]

\[\frac{3}{4}x = 4\frac{3}{6}\]

\[\frac{3}{4}x = \frac{27}{6}\]

\[x = \frac{27}{6}\ :\frac{3}{4} = \frac{27}{6} \cdot \frac{4}{3} = 3 \cdot 2\]

\[x = 6.\]