Пусть площадь всего поля Х
В первый день застелили 5х/12;
Второй день х - 5х/12;
Тогда за 3 дня можно выразить уравнением:
5х/12 + 9/15(х - 5х/12) + 1666 = х
5х/12 + 9/15*(12х - 5х)/12 + 1666 = х
5х/12 + 63х/180 + 1666 = х
5x/12 + 7x/20 - x = -1666
(25x + 21x - 60x)/60 = -1666
-14x/60 = -1666
7x/30 = 1666
x = 1666*30/7
x = 7 140 м² площадь всего поля
2 1/6 + 2 5/12 = (2 + 2) + (2/12 + 5/12) = 4 7/12
9 3/8 + 7 5/6 = (9 + 7) + (9/24 + 20/24) = 16 + 29/24 = 17 5/24
5 1/10 + 8 3/8 = (5 + 8) + (4/40 + 15/40) = 13 19/40
6 2/15 + 42 18/25 = (6 + 42) + (10/75 + 54/75) = 48 64/75
5 3/18 + 18 1/27 = (5 + 18) + (9/54 + 2/54) = 23 11/54
9 3/20 + 7 4/15 = (9 + 7) + (9/60 + 16/60) = 16 25/60 = 16 5/12
2 19/44 + 5 52/66 = (2 + 5) + (57/132 + 104/132) = 7 161/132 = 8 29/132
38 21/26 + 14 34/39 = (38 + 14) + (63/78 + 68/78) = 52 131/68 = 53 63/68
6 11/12 + 3 15/16 = (6 + 3) + (44/48 + 45/48) = 9 89/48 = 10 41/48
ответ:Можно так:
1) 12,03<x<12,23, x=12,13
2) 12,03<x<12,33, x=12,13, x=12,23
3) 12,03<x<12,43, x=12,13, x=12,23, x=12,33
4) 12,03<x<12,53, x=12,13, x=12,23, x=12,33, x=12,43
5) 12,03<x<12,63, x=12,13, x=12,23, x=12,33, x=12,43, x=12,53
6) 12,03<x<12,73, x=12,13, x=12,23, x=12,33, x=12,43, x=12,53, x=12,63
7) 12,03<x<12,83, x=12,13, x=12,23, x=12,33, x=12,43, x=12,53, x=12,63, x=12,73
8) 12,03<x<12,93, x=12,13, x=12,23, x=12,33, x=12,43, x=12,53, x=12,63, x=12,73, x=12,83
9) 12,13<x<12,33, x=12,23
10) 12,13<x<12,43, x=12,23, x=12,33
11) 12,13<x<12,53, x=12,23, x=12,33, x=12,43
12) 12,13<x<12,63, x=12,23, x=12,33, x=12,43, x=12,53
13) 12,13<x<12,73, x=12,23, x=12,33, x=12,43, x=12,53, x=12,63
14) 12,13<x<12,83, x=12,23, x=12,33, x=12,43, x=12,53, x=12,63, x=12,73
15) 12,13<x<12,93, x=12,23, x=12,33, x=12,43, x=12,53, x=12,63, x=12,73, x=12,83
16) 12,23<x<12,43, x=12,33
17) 12,23<x<12,53, x=12,33, x=12,43
18) 12,23<x<12,63, x=12,33, x=12,43, x=12,53
19) 12,23<x<12,73, x=12,33, x=12,43, x=12,53, x=12,63
20) 12,23<x<12,83, x=12,33, x=12,43, x=12,53, x=12,63, x=12,73
21) 12,23<x<12,93, x=12,33, x=12,43, x=12,53, x=12,63, x=12,73, x=12,83
22) 12,33<x<12,53, x=12,43
23) 12,33<x<12,63, x=12,43, x=12,53
24) 12,33<x<12,73, x=12,43, x=12,53, x=12,63
25) 12,33<x<12,83, x=12,43, x=12,53, x=12,63, x=12,73
26) 12,33<x<12,93, x=12,43, x=12,53, x=12,63, x=12,73, x=12,83
27) 12,43<x<12,63, x=12,53
28) 12,43<x<12,73, x=12,53, x=12,63
29) 12,43<x<12,83, x=12,53, x=12,63, x=12,73
30) 12,43<x<12,93, x=12,53, x=12,63, x=12,73, x=12,83
31) 12,53<x<12,73, x=12,63, x=12,73, x=12,83
32) 12,53<x<12,83, x=12,63, x=12,73
33) 12,53<x<12,93, x=12,63, x=12,73, x=12,83
34) 12,63<x<12,83, x=12,73
35) 12,63<x<12,93, x=12,73, x=12,83
36) 12,73<x<12,93, x=12,83
Пошаговое объяснение:
7/12*9/15=7/12*3/5=7/4*1/5=7/20 поля застелили во 2й день
7/12-7/20=35/60-21/60=14/60=7/30-застелили в 3й день
1666:7/30=1666*30/7=7140 кв.м-всё поле