Ответ: 1) x = 4; 2) x = 6; 3) x = -1/2; 4) x = 3 2/3
Решим первое уравнение:
\[10 : 1 \frac{7}{8} = 8x - 2x + x - 3x;\]
\[10 : \frac{15}{8} = 4x;\]
\[10 \cdot \frac{8}{15} = 4x;\]
\[\frac{16}{3} = 4x;\]
\[x = \frac{16}{3} : 4;\]
\[x = \frac{16}{3} \cdot \frac{1}{4};\]
\[x = \frac{4}{3}.\]
Ошибка в условии. Верно:\[x = \frac{4}{3}.\]
Решим второе уравнение:
\[3 \frac{2}{45}x + 1 \frac{7}{30}x = 6 \frac{1}{9};\]
\[\frac{137}{45}x + \frac{37}{30}x = \frac{55}{9};\]
\[\frac{274}{90}x + \frac{111}{90}x = \frac{55}{9};\]
\[\frac{385}{90}x = \frac{55}{9};\]
\[x = \frac{55}{9} : \frac{385}{90};\]
\[x = \frac{55}{9} \cdot \frac{90}{385};\]
\[x = \frac{1}{1} \cdot \frac{10}{7};\]
\[x = \frac{10}{7}.\]
Ошибка в условии. Верно:\[x = \frac{10}{7}.\]
Решим третье уравнение:
\[\left(8 \frac{2}{5} : x + 3 \frac{5}{9}\right) : 4 \frac{1}{6} = 1 \frac{1}{3};\]
\[\left(\frac{42}{5} : x + \frac{32}{9}\right) : \frac{25}{6} = \frac{4}{3};\]
\[\frac{42}{5} : x + \frac{32}{9} = \frac{4}{3} \cdot \frac{25}{6};\]
\[\frac{42}{5} : x + \frac{32}{9} = \frac{50}{9};\]
\[\frac{42}{5} : x = \frac{50}{9} - \frac{32}{9};\]
\[\frac{42}{5} : x = \frac{18}{9};\]
\[\frac{42}{5} : x = 2;\]
\[x = \frac{42}{5} : 2;\]
\[x = \frac{42}{5} \cdot \frac{1}{2};\]
\[x = \frac{21}{5}.\]
Ошибка в условии. Верно:\[x = \frac{21}{5}.\]
Решим четвертое уравнение:
\[\left(5 \frac{1}{6} - x\right) \cdot 2 \frac{7}{10} - 1 \frac{3}{14} = 3 \frac{2}{7};\]
\[\left(\frac{31}{6} - x\right) \cdot \frac{27}{10} - \frac{17}{14} = \frac{23}{7};\]
\[\left(\frac{31}{6} - x\right) \cdot \frac{27}{10} = \frac{23}{7} + \frac{17}{14};\]
\[\left(\frac{31}{6} - x\right) \cdot \frac{27}{10} = \frac{46}{14} + \frac{17}{14};\]
\[\left(\frac{31}{6} - x\right) \cdot \frac{27}{10} = \frac{63}{14};\]
\[\left(\frac{31}{6} - x\right) \cdot \frac{27}{10} = \frac{9}{2};\]
\[\frac{31}{6} - x = \frac{9}{2} : \frac{27}{10};\]
\[\frac{31}{6} - x = \frac{9}{2} \cdot \frac{10}{27};\]
\[\frac{31}{6} - x = \frac{1}{1} \cdot \frac{5}{3};\]
\[\frac{31}{6} - x = \frac{5}{3};\]
\[-x = \frac{5}{3} - \frac{31}{6};\]
\[-x = \frac{10}{6} - \frac{31}{6};\]
\[-x = -\frac{21}{6};\]
\[x = \frac{7}{2}.\]
Ошибка в условии. Верно:\[x = \frac{7}{2}.\]
Ответ: 1) x = 4/3; 2) x = 10/7; 3) x = 21/5; 4) x = 7/2