1.153 Решите уравнение:

Решение уравнений: a) $x + 2\frac{3}{16} = 3\frac{1}{8}$ $x = 3\frac{1}{8} - 2\frac{3}{16} = 3\frac{2}{16} - 2\frac{3}{16} = 2\frac{18}{16} - 2\frac{3}{16} = \frac{15}{16}$ б) $x - 1\frac{3}{4} = 2\frac{11}{12}$ $x = 2\frac{11}{12} + 1\frac{3}{4} = 2\frac{11}{12} + 1\frac{9}{12} = 3\frac{20}{12} = 4\frac{8}{12} = 4\frac{2}{3}$ в) $\frac{2}{9} : x = \frac{7}{18}$ $x = \frac{2}{9} : \frac{7}{18} = \frac{2}{9} \cdot \frac{18}{7} = \frac{2 \cdot 2}{7} = \frac{4}{7}$ г) $\frac{3}{5} \cdot x = \frac{6}{7}$ $x = \frac{6}{7} : \frac{3}{5} = \frac{6}{7} \cdot \frac{5}{3} = \frac{2 \cdot 5}{7} = \frac{10}{7} = 1\frac{3}{7}$ д) $x : (1\frac{2}{3} + \frac{4}{9}) = \frac{9}{38}$ $1\frac{2}{3} + \frac{4}{9} = 1\frac{6}{9} + \frac{4}{9} = 1\frac{10}{9} = 2\frac{1}{9} = \frac{19}{9}$ $x : \frac{19}{9} = \frac{9}{38} \implies x = \frac{9}{38} \cdot \frac{19}{9} = \frac{1}{2}$ е) $(8\frac{1}{2} - 7\frac{1}{4}) \cdot x = \frac{5}{12}$ $8\frac{2}{4} - 7\frac{1}{4} = 1\frac{1}{4} = \frac{5}{4}$ $\frac{5}{4} \cdot x = \frac{5}{12} \implies x = \frac{5}{12} : \frac{5}{4} = \frac{5}{12} \cdot \frac{4}{5} = \frac{1}{3}$