a)
В центре круга записано \(\frac{1}{7}\).
Нужно последовательно умножать числа в кругах на центральное число.
1. \(1\frac{2}{7} \cdot \frac{1}{7} = \frac{9}{7} \cdot \frac{1}{7} = \frac{9}{49}\)
2. \(\frac{2}{7} \cdot \frac{1}{7} = \frac{2}{49}\)
3. \(\frac{1}{7} \cdot \frac{1}{7} = \frac{1}{49}\)
4. \(2 \cdot \frac{1}{7} = \frac{2}{7}\)
5. \(\frac{5}{7} \cdot \frac{1}{7} = \frac{5}{49}\)
6. \(\frac{1}{9} \cdot \frac{1}{7} = \frac{1}{63}\)
7. \(\frac{6}{21} \cdot \frac{1}{7} = \frac{2}{7} \cdot \frac{1}{7} = \frac{2}{49}\)
8. \(1 \cdot \frac{1}{7} = \frac{1}{7}\)
b)
В центре круга записано \(\frac{1}{12}\).
Нужно последовательно складывать числа в кругах с центральным числом.
1. \(\frac{1}{4} + \frac{1}{12} = \frac{3}{12} + \frac{1}{12} = \frac{4}{12} = \frac{1}{3}\)
2. \(-\frac{7}{12} + \frac{1}{12} = -\frac{6}{12} = -\frac{1}{2}\)
3. \(-\frac{1}{6} + \frac{1}{12} = -\frac{2}{12} + \frac{1}{12} = -\frac{1}{12}\)
4. \(\frac{1}{6} + \frac{1}{12} = \frac{2}{12} + \frac{1}{12} = \frac{3}{12} = \frac{1}{4}\)
5. \(-\frac{1}{4} + \frac{1}{12} = -\frac{3}{12} + \frac{1}{12} = -\frac{2}{12} = -\frac{1}{6}\)
6. \(\frac{5}{12} + \frac{1}{12} = \frac{6}{12} = \frac{1}{2}\)
7. \(-1 + \frac{1}{12} = -\frac{12}{12} + \frac{1}{12} = -\frac{11}{12}\)
8. \(\frac{1}{3} + \frac{1}{12} = \frac{4}{12} + \frac{1}{12} = \frac{5}{12}\)