Решебник по алгебре 7 класс Мерзляк Задание 376

\[\boxed{\text{376\ (376).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]

\[1)\ x - \frac{7x + 1}{8} = \frac{4x + 3}{4}\ \ \ \ \ | \cdot 8\]

\[8x - 7x - 1 = 2 \cdot (4x + 3)\]

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

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

\[- 7x = 7\]

\[x = - 1.\]

\[Ответ:\ x = - 1.\]

\[2)\ \frac{2x + 1}{6} - \frac{3x + 1}{7} = 2\ \ \ \ \ | \cdot 42\]

\[7 \cdot (2x + 1) - 6 \cdot (3x + 1) = 84\]

\[14x + 7 - 18x - 6 = 84\]

\[- 4x = 84 - 1\]

\[- 4x = 83\]

\[x = - \frac{83}{4}\]

\[x = - 20,75\]

\[Ответ:\ x = - 20,75.\]

\[3)\ \frac{2x + 3}{3} - \frac{5x + 13}{6} + \frac{5 - 2x}{2} =\]

\[= 6\ \ \ \ \ \ | \cdot 6\]

\[4x + 6 - 5x - 13 + 15 - 6x =\]

\[= 36\]

\[- 7x = 36 - 6 + 13 - 15\]

\[- 7x = 28\]

\[x = - 4.\]

\[Ответ:x = - 4.\]

\[4)\ \frac{4x^{2} + 5x}{14} + \frac{10 - 2x^{2}}{7} =\]

\[= 5\ \ \ \ \ \ | \cdot 14\]

\[4x^{2} + 5x + 2 \cdot \left( 10 - 2x^{2} \right) = 70\]

\[5x = 50\]

\[x = 10.\]

\(Ответ:x = 10.\ \)