A) x=3 8/9- 1 5/9
x=2 3/9 = 2 1/3
b) y- 8 12/19 = 5 21/19 - 1 7/19
y-8 12/19=4 14/19
y=4 14/19+ 8 12/19
y=12 28/19
y=13 9/19
1) 8*3/4-3*(-2/3)=6+2=8
2) 8*(-2/3)-3*3/4=-16/3-9/4=> общий множитель 12=>(-16*4)-(9*3)/12=-64-27)/12=-91/12=-7 7/12
ответ:-7 целых 7/12
-2/9- 1 - 8/9=-(2/9+8/9+1)=-(10/9+1)=-(1 1/9 + 1)=- 2 1/9
- 7 1/6 - (9,(5) - х - 11 5/6) = 5,5
- 7 1/6 - 9 5/9 + х + 11 5/6 = 5,5
(11 5/6 - 7 1/6) - 9 5/9 + х = 5 5/10
4 2/3 - 9 5/9 + х = 5 1/2
4 6/9 - 9 5/9 + х = 5 1/2
- 4 8/9 + х = 5 1/2
х = 5 1/2 + 4 8/9
х = 5 9/18 + 4 16/18
х = 9 25/18
х = 10 целых 7/18
Ответ: В) 10 7/18.