Решебник по математике 6 класс Виленкин ФГОС Часть 1, 2 Часть 2. Задачи на повторение 100

\[\boxed{\mathbf{П.\ 100}}\]

\[\textbf{а)}\ 9 \cdot (2x - 2) + 3 \cdot (3 - 4x) =\]

\[= 24\]

\[18x - 18 + 9 - 12x = 24\]

\[6x = 24 + 9\]

\[6x = 33\]

\[x = 33\ :6\]

\[x = 5,5.\]

\[\textbf{б)}\ 4 \cdot \left( 1,5x - \frac{1}{5} \right) - 6\frac{13}{15} =\]

\[= 4 - \left( \frac{1}{6} - 1,5x \right)\]

\[6x - \frac{4}{5} - 6\frac{13}{15} = 4 - \frac{1}{6} + 1,5x\]

\[6x - 1,5x = 3\frac{5}{6} + \frac{12}{15} + 6\frac{13}{15}\]

\[4,5x = 3\frac{5}{6} + 6\frac{25}{15}\]

\[4,5x = 3\frac{5}{6} + 7\frac{10}{15}\]

\[4,5x = 3\frac{5}{6} + 7\frac{2}{3}\]

\[4,5x = 3\frac{5}{6} + 7\frac{4}{6}\]

\[4,5x = 10\frac{9}{6} = 11\frac{3}{6}\]

\[4,5x = 11,5\]

\[x = 11,5\ :4,5 = \frac{115}{45} = \frac{23}{9}\]

\[x = 2\frac{5}{9}.\]