а)

[tex]y \div 51.6 = 11.2 \div 34.4 \\ y = 11.2 \div 34.4 \times 51.6 \\ y = \frac{112 \times 516}{344 \times 10} \\ y = \frac{28 \times 3}{5} \\ \frac{84}{5} \\ y = 16 \frac{4}{5} \\ y = 16.8[/tex]

б)

[tex]m \div \frac{25}{6} = \frac{4}{7} \div \frac{20}{21} \\ m = \frac{4}{7} \div \frac{20}{21} \times \frac{25}{6} \\ m = \frac{4 \times 21 \times 25}{7 \times 20 \times 6} \\ m = \frac{5}{2} \\ m = 2.5[/tex]

в)

[tex]5 \frac{3}{5} \div 3 \frac{1}{2} = 5 \frac{1}{4} \div x \\ \frac{28}{5} \div \frac{7}{2} = \frac{21}{4} \div x \\ x = \frac{21}{4} \div ( \frac{28}{5} \div \frac{7}{2} ) \\ x = \frac{21}{4} \div ( \frac{28}{5} \times \frac{2}{7} ) \\ x = \frac{21 \times 5 \times 7}{4 \times 2 8\times 2} \\ x = \frac{105}{32} \\ x = 3 \frac{9}{32} [/tex]

г)

[tex]67.8\div a = 7.62 \div 6.35 \\ a = 67.8 \div (7.62 \div 6.35) \\ a = \frac{678 \times 635}{762 \times 10} \\ a = \frac{113}{2} \\ a = 56.5[/tex]

д)

[tex] \frac{3}{14} \div 3 \frac{1}{7} = k \div 3 \frac{2}{3} \\ \frac{3}{14} \div \frac{22}{7} = k \div \frac{11}{3} \\ k = \frac{3}{14} \div \frac{22}{7} \times \frac{11}{3} \\ k = \frac{3 \times 7 \times 11}{14 \times 22 \times 3} \\ k = \frac{1}{4} \\ k = 0.25[/tex]

е)

[tex]y \div 3 \frac{1}{5} = 4 \frac{1}{2} \div 2 \frac{1}{4} \\ y \div \frac{16}{5} = \frac{9}{2} \div \frac{9}{4} \\ y = \frac{9}{2} \div \frac{9}{4} \times \frac{16}{5} \\ y = \frac{9 \times 4 \times 16}{2 \times 9 \times 5} \\ y = \frac{32}{5} \\ y = 6.4[/tex]