2 целых 2/3-5/9*2целых4/7 ------------------------ (2целых1/7+1целая 2/3 ) :5

2 2/3-5/9* 2 4/7 -(2 1/7+1 2/3): 5= 2 2/3-10/7 -3 17/21= -2 12/21

2ц 2/3-5/9*2ц4/7=1ц5/211. 5/9*18/7=10/7=1ц3/72. 2ц2/3-1ц3/7= 2ц14/21-1ц9/21= 1ц5/21(2целых1/7+1целая 2/3 ) :5=0,81. 2ц1/7+ 1ц2/3= 2ц7/21+1ц14/21= 42. 4:5=0,8