Решение:

Чтобы привести дроби к наименьшему общему знаменателю, нужно найти наименьшее общее кратное (НОК) знаменателей и привести каждую дробь к этому знаменателю.

1) $$rac{13}{24}$$ и $$rac{11}{64}$$

• НОК(24, 64) = 192
• $$rac{13}{24} = \frac{13 \cdot 8}{24 \cdot 8} = \frac{104}{192}$$
• $$rac{11}{64} = \frac{11 \cdot 3}{64 \cdot 3} = \frac{33}{192}$$

2) $$rac{5}{72}$$ и $$rac{7}{108}$$

• НОК(72, 108) = 216
• $$rac{5}{72} = \frac{5 \cdot 3}{72 \cdot 3} = \frac{15}{216}$$
• $$rac{7}{108} = \frac{7 \cdot 2}{108 \cdot 2} = \frac{14}{216}$$

3) $$rac{117}{300}$$ и $$rac{11}{250}$$

• НОК(300, 250) = 1500
• $$rac{117}{300} = \frac{117 \cdot 5}{300 \cdot 5} = \frac{585}{1500}$$
• $$rac{11}{250} = \frac{11 \cdot 6}{250 \cdot 6} = \frac{66}{1500}$$

4) $$rac{11}{140}$$ и $$rac{19}{42}$$

• НОК(140, 42) = 420
• $$rac{11}{140} = \frac{11 \cdot 3}{140 \cdot 3} = \frac{33}{420}$$
• $$rac{19}{42} = \frac{19 \cdot 10}{42 \cdot 10} = \frac{190}{420}$$

5) $$rac{12}{81}$$ и $$rac{23}{180}$$

• НОК(81, 180) = 1620
• $$rac{12}{81} = \frac{12 \cdot 20}{81 \cdot 20} = \frac{240}{1620}$$
• $$rac{23}{180} = \frac{23 \cdot 9}{180 \cdot 9} = \frac{207}{1620}$$

6) $$rac{19}{81}$$ и $$rac{25}{297}$$

• НОК(81, 297) = 2673
• $$\frac{19}{81} = \frac{19 \cdot 33}{81 \cdot 33} = \frac{627}{2673}$$
• $$\frac{25}{297} = \frac{25 \cdot 9}{297 \cdot 9} = \frac{225}{2673}$$

7) $$\frac{5}{189}$$ и $$\frac{15}{441}$$

• НОК(189, 441) = 1323
• $$\frac{5}{189} = \frac{5 \cdot 7}{189 \cdot 7} = \frac{35}{1323}$$
• $$\frac{15}{441} = \frac{15 \cdot 3}{441 \cdot 3} = \frac{45}{1323}$$

8) $$\frac{105}{117}$$ и $$\frac{21}{195}$$

• НОК(117, 195) = 585
• $$\frac{105}{117} = \frac{105 \cdot 5}{117 \cdot 5} = \frac{525}{585}$$
• $$\frac{21}{195} = \frac{21 \cdot 3}{195 \cdot 3} = \frac{63}{585}$$