97. Упростите выражение: a) $$\frac{4}{9} m × \frac{18}{25} × \frac{5}{8}$$; б) $$1\frac{5}{7} x × 1\frac{3}{4} × 5$$

Решение:

1. \(\frac{4}{9} m × \frac{18}{25} × \frac{5}{8} = m × \frac{4 × 18 × 5}{9 × 25 × 8} = m × \frac{360}{1800} = m × \frac{1}{5}\)
2. \(1\frac{5}{7} x × 1\frac{3}{4} × 5 = x × \frac{12}{7} × \frac{7}{4} × 5 = x × \frac{12 × 7 × 5}{7 × 4} = x × \frac{420}{28} = x × 15\)

Ответ: а) $$\frac{1}{5}m$$; б) $$15x$$.