В))
2 3/4 : { ( 4 5/7- 1 11/14) • 4 2/3 + ( 3 2/9 - 1 5/6) • 18/25}=1/4.
1)) 4 5/7 - 1 11/14=
4 (5•2)/(7•2) - 1 11/14=
4 10/14- 1 11/14=
3 (14•1+10)/14 - 1 11/14=
3 24/14- 1 11/14= 2 13/14
2)) 2 13/14• 4 2/3=
(2•14+13)/14 • (4•3+2)/3 =
41/14• 14/3= 41/1• 1/3= 41/3= 13 2/3
3)) 3 2/9- 1 5/6=
3 (2•2)/(9•2) - 1 (5•3)/(6•3)=
3 4/18- 1 15/18=
2 (1•18+4)/18- 1 15/18=
2 22/18- 1 15/18= 1 7/18
4)) 1 7/18• 18/25= (1•18+7)/18• 18/25=
25/18• 18/25= 1/1• 1/1= 1
5)) 13 2/3+ 1= 14 2/3
6)) 2 3/4 : 14 2/3=
(2•4+3)/4 : (14•3+2)/3=
11/4: 44/3= 11/4• 3/44= 1/1• 1/4= 1/4.
Ответ: =1/4.