Номер 274

Краткое условие: 1) \( 7 \frac{4}{21}+2 \frac{1}{6} \); 2) \( 3 \frac{5}{36}-1 \frac{19}{45} \); 3) \( 3 \frac{7}{30}-\left(4 \frac{1}{6}-1 \frac{2}{15}\right)+\left(4 \frac{5}{9}-4 \frac{5}{9}\right) \); 4) \( 2 \frac{7}{12}+6 \frac{8}{9}-\left(5-1 \frac{7}{36}-3 \frac{1}{3}\right) \).