A)4x-12=18-x б) 21x-5*(2x-7)=24 в)19y-(16y-(17-3y))+17+5y=y+34+4y

4х - 12 = 18 - х

4х + х = 18 + 12

5х = 30

х = 30/5

х = 6

21х - 5(2х - 7) = 24

21х - 10х + 35 = 24

11х = 24 - 35

11х = -11

х = -11/11

х = -1

19у - (16у - (17 - 3у)) + 17 + 5у = у + 34 + 4у

19у - (16у - 17 + 3у) + 17 + 5у = 5у + 34

24у - 16у + 17 - 3у + 17 = 5у + 34

5у - 5у = 34 - 17 - 17

0 = 0

а) 4х+х=18+12

5х= 30

х=30:5

х=6

б) 21х-10х+35=24

21х-10х=24-35

11х= -11

х= -11:11

х= -1