решите уравнения x + (x+1) + (x+2) = 9 (z-2) + (z-1) + z=-3 21 + (20-4x) - (11-2x) = 0 2u-3 (7-2u) = 3 12-y=5 (4-2y) + 10 2-2 (x-8) = 4x-4

1. x + (x+1) + (x+2) = 9

x+x+1+x+2=9

3x+3=9

3x=9-3

3x=6

x=6:3

x=2

2. (z-2) + (z-1) + z=-3

z-2+z-1+z=-3

3z-3=-3

3z=-3+3

3z=0

z=0

3. 21 + (20-4x) - (11-2x) = 0

21+20-4x-11+2x=0

-2x+30=0

-2x=-30

x=-30: (-2)

x=15

4. 2u-3 (7-2u) = 3

2u-21+6u=3

8u=3+21

8u=24

u=24:8

u=3

5.12-y=5 (4-2y) + 10

12-y=20-10y+10

-y+10y=30-12

9y=18

y=18:9

y=2

6. 2-2 (x-8) = 4x-4

2-2x+16=4x-4

-2x-4x=-4-16-2

-6x=-22

x=-22: (-6)

x=11/3