№ 85
1 - 5/8 = 3/8
1 + 2 5/16 = 3 5/16
8 - 5/12 = 7 7/12
4 - 1 2/3 = 2 1/3
№ 86
5 2/15 + 3 5/12 = 8 11/20
9 4/21 - 4 11/14 = 4 17/ 42
5 13/35 + 2 13/14 = 8 3 /10
5 5/33 - 4 7/22 = 5/6
№87
7-х = 3 1/3
х = 7 - 3 1/3
х = 2 2/3
у + 3 5/9 = 5 4/9
у = 5 4/9 - 3 5/9
у = 1 8/9
№ 90
а) 8 14/25 + 3,148 - 1,2 =
8,56+3,148-1,2=10,508
б) 8 7/15 + 4 1/3 -0,8 = 8,47+ 4,3-0,8=11,97
№ 93
9 5/21 - ( 10 2/3 - 3 5/28) = 1 3/4
10 2/3 - 3 5/28 = 7 41/84
9 5/21 - 7 41/84 = 1 3/4
6 13/15 + 3 7/12 - 4 9/20= 6
6 13/15 + 3 7/12 = 10 9/20
10 9/20 - 4 9/20= 6
№ 94
3 5/6 - 2,25 + 5 5/12 = 3,83-2,25+5,41=6,99