4. Выполните действия: а) 53,104 + 4,6 · (12 − 13,23 : 1,26); б) (6 1/3 − 4 5/9) · (3/7 + 2 1/21).

а)

\(13.23 : 1.26 = 10.5\).

\(12 - 10.5 = 1.5\).

\(4.6 \cdot 1.5 = 6.9\).

\(53.104 + 6.9 = 60.004\).

Ответ: 60,004.

б)

\(6\frac{1}{3} = \frac{19}{3}\), \(4\frac{5}{9} = \frac{41}{9}\), \(2\frac{1}{21} = \frac{43}{21}\).

\(\frac{19}{3} - \frac{41}{9} = \frac{57}{9} - \frac{41}{9} = \frac{16}{9}\).

\(\frac{3}{7} + \frac{43}{21} = \frac{9}{21} + \frac{43}{21} = \frac{52}{21}\).

\(\frac{16}{9} \cdot \frac{52}{21} = \frac{832}{189} = 4\frac{76}{189}\).

Ответ: \(4\frac{76}{189}\).