3. Решите уравнение: 63 1)x=; 3 3)x = 12; 7 15 5) x : = ; 55 15 28 4 2 168 2)x = 1; 4) 3x = ; 6): x = ;

Решение:

1. \[\frac{6}{5}x = \frac{3}{5}\] \[x = \frac{3}{5} : \frac{6}{5}\] \[x = \frac{3}{5} \times \frac{5}{6}\] \[x = \frac{3 \times 5}{5 \times 6}\] \[x = \frac{1 \times 1}{1 \times 2}\] \[x = \frac{1}{2}\]
2. \[\frac{4}{7}x = 1\] \[x = 1 : \frac{4}{7}\] \[x = 1 \times \frac{7}{4}\] \[x = \frac{7}{4}\]
3. \[\frac{3}{4}x = 12\] \[x = 12 : \frac{3}{4}\] \[x = 12 \times \frac{4}{3}\] \[x = \frac{12 \times 4}{3}\] \[x = \frac{4 \times 4}{1}\] \[x = 16\]
4. \[3x = \frac{2}{3}\] \[x = \frac{2}{3} : 3\] \[x = \frac{2}{3} \times \frac{1}{3}\] \[x = \frac{2}{9}\]
5. \[x : \frac{7}{15} = \frac{15}{28}\] \[x = \frac{15}{28} \times \frac{7}{15}\] \[x = \frac{15 \times 7}{28 \times 15}\] \[x = \frac{1 \times 1}{4 \times 1}\] \[x = \frac{1}{4}\]
6. \[\frac{16}{27} : x = \frac{8}{9}\] \[x = \frac{16}{27} : \frac{8}{9}\] \[x = \frac{16}{27} \times \frac{9}{8}\] \[x = \frac{16 \times 9}{27 \times 8}\] \[x = \frac{2 \times 1}{3 \times 1}\] \[x = \frac{2}{3}\]