8y=-62,4+5y
8y-5y=-62,4
3y=62,4
y=-20,8
11/23 * 3 2/7 : 5 1/2 = 11/23 * 23/7 : 11/2 = 11/7 : 11/2 = 11/7 * 2/11 = 2/7
3/5 * (2 2/3 : 3 1/5) = 3/5 * (8/3 : 16/5) = 3/5 * (8/3 * 5/16) = 3/5 * 5/6 = 1/2
1 1/8 * (9 1/3 : 1 3/4) = 9/8 * (28/3 : 7/4) = 9/8 * (28/3 * 4/7) = 9/8 * 16/3 = 6
Ответ:
3) ( 4\5-х)+13\20=7\10
4\5-х=7\10-13\20 (7\10-13\20=14\20-13\20=1\20)
4\5-х=1\20
х=4\5-1\20 ( 4\5-1\20=16\20-1\20=15\20=3\4)
х=3\4
4) 2\3-(2\9+х)=1\3
2\9+х=2\3-1\3
2\9+х=1\3
х=1\3-2\9 (1\3-2\9=3\9-2\9=1\9)
х=1\9