1) 5/18 + x = 17/18 2) 5 3/9 + x = 17 1/9 3) 16 4/18 - x = 4 13/18 4) x + 17 5/8 = 19 3/8

Решим уравнения:

1. $$\frac{5}{18} + x = \frac{17}{18}$$ $$x = \frac{17}{18} - \frac{5}{18}$$ $$x = \frac{17-5}{18}$$ $$x = \frac{12}{18}$$ $$x = \frac{2}{3}$$
2. $$5 \frac{3}{9} + x = 17 \frac{1}{9}$$ $$x = 17 \frac{1}{9} - 5 \frac{3}{9}$$ $$x = 16 \frac{10}{9} - 5 \frac{3}{9}$$ $$x = (16 - 5) + (\frac{10}{9} - \frac{3}{9})$$ $$x = 11 + \frac{10-3}{9}$$ $$x = 11 \frac{7}{9}$$
3. $$16 \frac{4}{18} - x = 4 \frac{13}{18}$$ $$x = 16 \frac{4}{18} - 4 \frac{13}{18}$$ $$x = 15 \frac{22}{18} - 4 \frac{13}{18}$$ $$x = (15 - 4) + (\frac{22}{18} - \frac{13}{18})$$ $$x = 11 + \frac{22-13}{18}$$ $$x = 11 \frac{9}{18}$$ $$x = 11 \frac{1}{2}$$
4. $$x + 17 \frac{5}{8} = 19 \frac{3}{8}$$ $$x = 19 \frac{3}{8} - 17 \frac{5}{8}$$ $$x = 18 \frac{11}{8} - 17 \frac{5}{8}$$ $$x = (18 - 17) + (\frac{11}{8} - \frac{5}{8})$$ $$x = 1 + \frac{11-5}{8}$$ $$x = 1 \frac{6}{8}$$ $$x = 1 \frac{3}{4}$$

Ответ: 1) $$\frac{2}{3}$$, 2) $$11 \frac{7}{9}$$, 3) $$11 \frac{1}{2}$$, 4) $$1 \frac{3}{4}$$