(73,6 - 72 5/9) : 6 4/15 + 7/13 · (20 2/3 - 19 3/7) = 5/6
1) 73,6 - 72 5/9 = 73 3/5 - 72 5/9 = 73 27/45 - 72 25/45 = 1 2/45
2) 1 2/45 : 6 4/15 = 47/45 : 94/15 = 47/45 · 15/94 = (1·3)/(9·2) = 3/18 = 1/6
- - - - - - -
3) 20 2/3 - 19 3/7 = 20 14/21 - 19 9/21 = 1 5/21
4) 7/13 · 1 5/21 = 7/13 · 26/21 = (1·2)/(1·3) = 2/3
- - - - - - -
5) 1/6 + 2/3 = 1/6 + 4/6 = 5/6
225214 первое
33210 второе
45 третье
(5х+2х)*14=294
7x*14=294
7x=294:14
7x=21
x=21:7
x=3
(12y-5y):4=21
7y:4=21
7y=21*4
7y=84
y=84:7
y=12
(19х+6х):35=5
25x:35=5
25x=5*35
25x=175
x=175:25
x=7
234:(21y-8y)=3
234:13y=3
13y= 234:3
13y=78
y=78:3
y=26
1)x=0,8:4/3
x=3/5.
2)3/25y=1,8
y=1/15