toripetlinskaya35 397.
1)3(х-9)=69
3х-27=69
3х-27-69=0
3х-96=0
3х=96
х=32.

2)(2у+5)×4=100
8у+20=100
8у+20-100=0
8у-80=0
8у=80
у=10

3)56(3х+8)=4984
168х+448=4984
168х+448-4984=0
168х-4536=0
168х=4536
х=27

4)12×(2х-4)=336
24х-48=336
24х-48-336=0
24х-384=0
24х=384
х=16

398.

1)5×(а+2)+9=64
5а+10+9=64
5а+10+9-64=0
5а-45=0
5а=45
а=9

2)2×(3х+1)-3=11
6х+2-3=11
6х+2-3-11=0
6х-12=0
6х=12
х=2

3)17×(5х-3)-34=1700
85х-51-34=1700
85х-51-34-1700=0
85х-1785=0
85х=1785
х=21

4)6×(3х+6)+22=2344
18х+36+22=2344
18х+36+22-2344=0
18х-2286=0
18х=2286
х=127

alenapresnova94 №397.
1) 3×(х-9)=69
х-9 = 69:3
х-9 = 23
х = 23+9
х = 32

2) (2у+5)×4 = 100
2у+5 = 100:4
2у+5 = 25
2у = 25-5
2у = 20
у = 20:2
у = 10

3) 56×(3х+8) = 4984
3х+8 = 4984:56
3х+8 = 89
3х = 89-8
3х = 81
х = 81:3
х = 27

4) 12×(2х-4) = 336
2х-4 = 336:12
2х-4 = 28
2х = 28+4
2х = 32
х = 32:2
х = 16

№398
1) 5×(а+2)+9 = 64
5×(а+2) = 64-9
5×(а+2) = 55
а+2 = 55:5
а+2 = 11
а = 11-2
а = 9

2) 2×(3х-1)-3 = 11
2×(3х-1) = 11+3
2×(3х-1) = 14
3х-1 = 14:2
3х+1 = 7
3х = 7-1
3х = 6
х = 6:3
х = 2

3) 17×(5х-3)-34 = 1700
17×(5х-3) = 1700+34
17×(5х-3) = 1734
5х-3 = 1734:17
5х-3 = 102
5х = 102+3
5х = 105
х = 105:5
х = 21

6) 6×(3х+6)+22 = 2344
6×(3х+6) = 2344-22
6×(3х+6) = 2322
3х+6 = 2322:6
3х+6 = 387
3х = 387-6
3х = 381
х = 381:3
х = 127