Сократите дробь.

Решение:

Образец: \( \frac{32-2}{60} = \frac{30}{60} = \frac{1}{2} \)

1. \( \frac{5+7}{14} = \frac{12}{14} = \frac{6}{7} \)
2. \( \frac{156-39}{390} = \frac{117}{390} = \frac{3 \cdot 39}{10 \cdot 39} = \frac{3}{10} \)
3. \( \frac{72+48}{720} = \frac{120}{720} = \frac{12}{72} = \frac{1}{6} \)
4. \( \frac{52-12}{12} = \frac{40}{12} = \frac{10 \cdot 4}{3 \cdot 4} = \frac{10}{3} \)
5. \( \frac{639+207}{639} = \frac{846}{639} = \frac{279 \cdot 3}{213 \cdot 3} = \frac{279}{213} = \frac{93 \cdot 3}{71 \cdot 3} = \frac{93}{71} \)
6. \( \frac{11\cdot 25 - 7 \cdot 25}{25 \cdot 44 - 25 \cdot 14} = \frac{25(11-7)}{25(44-14)} = \frac{4}{30} = \frac{2}{15} \)
7. \( \frac{37 \cdot 8}{37 \cdot 16 + 37 \cdot 4} = \frac{37 \cdot 8}{37(16+4)} = \frac{8}{20} = \frac{2}{5} \)
8. \( \frac{9 \cdot 4 + 6 \cdot 4}{8 \cdot 81 - 8 \cdot 56} = \frac{4(9+6)}{8(81-56)} = \frac{4 \cdot 15}{8 \cdot 25} = \frac{60}{200} = \frac{6}{20} = \frac{3}{10} \)
9. \( \frac{12 \cdot 5 - 12 \cdot 3}{12 \cdot 4} = \frac{12(5-3)}{12 \cdot 4} = \frac{2}{4} = \frac{1}{2} \)
10. \( \frac{2 \cdot 24 + 5 \cdot 6}{25 \cdot 64 - 25 \cdot 4} = \frac{48+30}{25(64-4)} = \frac{78}{25 \cdot 60} = \frac{78}{1500} = \frac{13 \cdot 6}{250 \cdot 6} = \frac{13}{250} \)
11. \( \frac{64 \cdot 8 + 64 \cdot 10}{32 \cdot 24 + 32 \cdot 48} = \frac{64(8+10)}{32(24+48)} = \frac{64 \cdot 18}{32 \cdot 72} = \frac{2 \cdot 18}{72} = \frac{36}{72} = \frac{1}{2} \)
12. \( \frac{61 \cdot 2 + 61 \cdot 30}{61 + 61 \cdot 3} = \frac{61(2+30)}{61(1+3)} = \frac{32}{4} = 8 \)