( 4 - 14/33• 1 1/21)• 5 5/8=20. 1)) 14/33• 1 1/21= 14/33• (1•21+1)/21=14/33• 22/21= Сокращаем 14 и 21 на 7; 33 и 22 на 11;2/3• 2/3= 4/9.2)) 4- 4/9= 3 9/9- 4/9= 3 5/9.3)) 3 5/9• 5 5/8= (3•9+5)/9• (5•8+5)/8=32/9• 45/8=Сокращаем 32 и 8 на 8; 9 и 45 на 9; 4/1• 5/1= 4•5=20.