39. Реши уравнения. А: x + 1/3 = 5/6; (1/9) · b = 1/3; b − 1/8 = 1/4; y + 1/3 = 1/2; c · 4 = 1/5. Б: 1/5 − x = 1/10; y − 1/12 = 5/6; a + 1/6 = 7/12; b : 1/5 = 1/6; 4 : b = 1/4. В: 7/10 − c = 1/5; b − 1/6 = 1/6; 1/8 + a = 1/2; x · 1/3 = 1/5; 5 · y = 1/2. Г: y : 8 = 1/10; y : 3 = 2/7; 1/6 + x = 1/2; a − 4/9 = 1/3; c − 1/6 = 1/3.

А

1. \(x=\frac{5}{6}-\frac{1}{3}=\frac{1}{2}\).
2. \(b=\frac{1}{3}:\frac{1}{9}=3\).
3. \(b=\frac{1}{4}+\frac{1}{8}=\frac{3}{8}\).
4. \(y=\frac{1}{2}-\frac{1}{3}=\frac{1}{6}\).
5. \(c=\frac{1}{5}:4=\frac{1}{20}\).

Б

1. \(x=\frac{1}{5}-\frac{1}{10}=\frac{1}{10}\).
2. \(y=\frac{5}{6}+\frac{1}{12}=\frac{11}{12}\).
3. \(a=\frac{7}{12}-\frac{1}{6}=\frac{5}{12}\).
4. \(b=\frac{1}{6}\cdot\frac{1}{5}=\frac{1}{30}\).
5. \(4:b=\frac{1}{4}\), значит \(b=4:\frac{1}{4}=16\).

В

1. \(c=\frac{7}{10}-\frac{1}{5}=\frac{1}{2}\).
2. \(b=\frac{1}{6}+\frac{1}{6}=\frac{1}{3}\).
3. \(a=\frac{1}{2}-\frac{1}{8}=\frac{3}{8}\).
4. \(x=\frac{1}{5}:\frac{1}{3}=\frac{3}{5}\).
5. \(y=\frac{1}{2}:5=\frac{1}{10}\).

Г

1. \(y=\frac{1}{10}\cdot8=\frac{4}{5}\).
2. \(y=\frac{2}{7}\cdot3=\frac{6}{7}\).
3. \(x=\frac{1}{2}-\frac{1}{6}=\frac{1}{3}\).
4. \(a=\frac{1}{3}+\frac{4}{9}=\frac{7}{9}\).
5. \(c=\frac{1}{3}+\frac{1}{6}=\frac{1}{2}\).