4. Упростите выражение: 1) \frac{11}{18}b - \frac{5}{18}b; 2) \frac{5}{14}y + \frac{9}{28}y; 3) \frac{5}{18}c + \frac{7}{24}c - \frac{11}{36}c; 4) 2\frac{7}{16}y + 3\frac{5}{20}y + 1\frac{3}{8}y.

1)

• $$\frac{11}{18}b - \frac{5}{18}b = (\frac{11}{18} - \frac{5}{18})b = \frac{6}{18}b = \frac{1}{3}b$$

Ответ:$$\frac{1}{3}b$$

2)

• $$\frac{5}{14}y + \frac{9}{28}y = (\frac{5}{14} + \frac{9}{28})y = (\frac{10}{28} + \frac{9}{28})y = \frac{19}{28}y$$

Ответ:$$\frac{19}{28}y$$

3)

• $$\frac{5}{18}c + \frac{7}{24}c - \frac{11}{36}c = (\frac{5}{18} + \frac{7}{24} - \frac{11}{36})c = (\frac{20}{72} + \frac{21}{72} - \frac{22}{72})c = \frac{19}{72}c$$

Ответ:$$\frac{19}{72}c$$

4)

• 2$$\frac{7}{16}y + 3\frac{5}{20}y + 1\frac{3}{8}y = 2\frac{7}{16}y + 3\frac{1}{4}y + 1\frac{3}{8}y = (2\frac{7}{16} + 3\frac{4}{16} + 1\frac{6}{16})y = (2 + 3 + 1 + \frac{7}{16} + \frac{4}{16} + \frac{6}{16})y = (6 + \frac{17}{16})y = (6 + 1\frac{1}{16})y = 7\frac{1}{16}y$$

Ответ: 7$$\frac{1}{16}y$$