[tex](\frac{5}{21} + \frac{3}{14}) * 1\frac{2}{19} \\\\(\frac{10}{42} + \frac{9}{42}) * \frac{21}{19} \\\\\frac{19}{42} * \frac{21}{19} = \frac{21}{42} = \frac{1}{2}[/tex]

Ответ:

1/2

Пошаговое объяснение:

1) 5/21 + 3/14 = 10/42 + 9/42 = 19/42

2) 19/42 * 1. 2/19 = 19/42 * 21/19 = 1/2 * 1/1 = 1/2