243. Сократите дроби: б) 42/720, 75/300, 40/64, 3/243, 18/300, 45/900, 120/180

б)

• $$ \frac{42}{720} = \frac{6 \cdot 7}{6 \cdot 120} = \frac{7}{120} $$
• $$ \frac{75}{300} = \frac{75 \cdot 1}{75 \cdot 4} = \frac{1}{4} $$
• $$ \frac{40}{64} = \frac{8 \cdot 5}{8 \cdot 8} = \frac{5}{8} $$
• $$ \frac{3}{243} = \frac{3 \cdot 1}{3 \cdot 81} = \frac{1}{81} $$
• $$ \frac{18}{300} = \frac{2 \cdot 9}{2 \cdot 150} = \frac{9}{150} = \frac{3 \cdot 3}{3 \cdot 50} = \frac{3}{50} $$
• $$ \frac{45}{900} = \frac{45 \cdot 1}{45 \cdot 20} = \frac{1}{20} $$
• $$ \frac{120}{180} = \frac{60 \cdot 2}{60 \cdot 3} = \frac{2}{3} $$