АН
Алексей Нестеров
(2,1*1 1/3-1,4*1/11)*(0,7*1 3/11)=
2,1*1ц1/3=2ц1/10*1ц1/3=21/10*4/3=7*2/5=14/5=2ц4/5=2,8
1,4*1/11=1ц4/10*1/11=1ц2/5*1/11=7/5*1/11=7/55
2,8-7/55=2ц4/5-7/55=2ц44/55-7/55=2ц+(44/55-7/55)=2+37/55=2ц37/55
2ц37/55*1ц3/11=147/55*14/11=2058/605=3ц243/605
Удачи!