225. Сократите: 1) 4⋅5/25⋅6; 2) 8⋅13/39⋅2; 3) 3⋅38/19⋅27; 4) 2⋅3⋅4⋅5/4⋅5⋅6⋅7; 5) 6⋅7⋅8⋅9⋅10/7⋅9⋅11⋅12; 6) 3⋅16−8⋅3/27

1) $$rac{4 cdot 5}{25 cdot 6} = rac{4 cdot 5}{5 cdot 5 cdot 2 cdot 3} = rac{2 cdot 2 cdot 5}{5 cdot 5 cdot 2 cdot 3} = rac{2}{5 cdot 3} = rac{2}{15}$$

2) $$rac{8 cdot 13}{39 cdot 2} = rac{8 cdot 13}{3 cdot 13 cdot 2} = rac{4 cdot 2 cdot 13}{3 cdot 13 cdot 2} = rac{4}{3}$$

3) $$rac{3 cdot 38}{19 cdot 27} = rac{3 cdot 2 cdot 19}{19 cdot 3 cdot 9} = rac{2}{9}$$

4) $$rac{2 cdot 3 cdot 4 cdot 5}{4 cdot 5 cdot 6 cdot 7} = rac{2 cdot 3 cdot 4 cdot 5}{4 cdot 5 cdot 2 cdot 3 cdot 7} = rac{1}{7}$$

5) $$rac{6 cdot 7 cdot 8 cdot 9 cdot 10}{7 cdot 9 cdot 11 cdot 12} = rac{6 cdot 7 cdot 8 cdot 9 cdot 10}{7 cdot 9 cdot 11 cdot 6 cdot 2} = rac{8 cdot 10}{11 cdot 2} = rac{8 cdot 5}{11} = rac{40}{11}$$

6) $$rac{3 cdot 16 - 8 cdot 3}{27} = rac{3 cdot 8 cdot 2 - 8 cdot 3}{27} = rac{3 cdot 8 cdot (2 - 1)}{27} = rac{3 cdot 8}{27} = rac{8}{9}$$