1) \(\frac{2}{3}=\frac{10}{15}=\frac{30}{45}=\frac{84}{126}\).
2) а) НОЗ \(=15\): \(\frac{2}{3}=\frac{10}{15}\), \(\frac{4}{5}=\frac{12}{15}\).
б) НОЗ \(=36\): \(\frac{5}{9}=\frac{20}{36}\), \(\frac{7}{36}=\frac{7}{36}\).
в) НОЗ \(=60\): \(\frac{5}{12}=\frac{25}{60}\), \(\frac{3}{20}=\frac{9}{60}\).
3) а) \(\frac{2}{5}=0.4\); б) \(\frac{13}{20}=0.65\); в) \(\frac{36}{25}=1.44\); г) \(\frac{18}{450}=0.04\).