А)(5.2-3 целых 1/3):1 целая 1/3=(156/30-100/30):40/30=56/30:40/30=56/30*30/40=7/5=1 целая 2/5=1.4
Б)(3/8+2 целых 1/7*1 целая 1/20)*1 целая 1/3=(3/8+15/7*21/20)*4/3=(3/8+9/4)*4/3=(3/8+18/8)*4/3=21/8*4/3=7/2=3 целых 1/2=3.5
В)(9-1 целая 1/3*4 целых 2/7)*21/46=(9-4/3*30/7)*21/46=(9-40/7)*21/46=(9-5 целых 5/7)*21/46=3 целых 2/7 * 21/46=23/7*21/46=3/2=1 целая 1/2=1.5