1)
а)=39.37-18.07=21.3
б)=83.8+(136.8-4.7)=83.8+132.1=215.9
в)==206.4+43.6=250
27,703 - х = 18,926
х = 27,703 - 18,926
х = 8,777
==================
27,703 - 8,777 = 18,926
18,926=18,926
(312,45 -0,00045)+х = 518,13955 - 5,69
х= 518,13955 - 5,69 - (312,45 -0,00045)
х = 518,13955 - 5,69 - 312,45 + 0,00045
х = (518,13955 +0,00045) - (312,45 + 5,69)
х = 518,14 - 318,14
х= 200
=================================
(312,45 -0,00045) + 200 = 518,13955 - 5,69
(312,45000 - 0,00045) + 200 = 518,13955 - 5,69000
312,44955 +200,00000 = 512,44955
512,44955= 512,44955
12 7/12-4 1/8-4 1/3=
12 14/24-4 3/24-4 8/24=
(12-4-4) и (14/24-3/24-8/24)=
4 3/24=4 1/8
11-(4 5/6+3 3/10)=
11-(7 25/30+9/30)=
11-7 34/30=11-8 4/30=
11-8 2/15=10 15/15-8 2/15=2 13/15
1) 850×10=8500 (км)
2) 8500-630=7870 (км)
Ответ:7870 километров больше проделал самолёт чем прошел поезд.
Удачи