1) 5 (x-1) + 7=3 (x+1) + 1; 2) 2 (x+1) + 3=3 (x-1) + 6; 3) 3 (4-x) + 1=2 (3-x) + 6; 4) 7 (5-x) + 2=5 (6-x) + 1

1) 5 (x - 1) + 7 = 3 (x + 1) + 1, 2) 2 (x + 1) + 3 = 3 (x - 1) + 6,

5 х - 5 + 7 = 3 х + 3 + 1, 2 х + 2 + 3 = 3 х - 3 + 6,

5 х + 2 = 3 х + 4, 2 х + 5 = 3 х + 3,

5 х - 3 х = 4 - 2, 2 х - 3 х = 3 - 5,

2 х = 2, - х = - 2,

х = 2 : 2, х = 2;

х = 1;

3) 3 (4 - x) + 1 = 2 (3 - x) + 6, 4) 7 (5 - x) + 2 = 5 (6 - x) + 1,

12 - 3 х + 1 = 6 - 2 х + 6, 35 - 7 х + 2 = 30 - 5 х + 1,

3 - 3 х = 12 - 2 х, 37 - 7 х = 31 - 5 х,

-3 х + 2 х = 12 - 3, - 7 х + 5 х = 31 - 37,

-х = 9, - 2 х = - 6,

х = 9; х = - 6 : (-2),

х = 3.

1) 5 (x-1) + 7 = 3 (х+1) + 1

5 х-5+7=3 х+3+1

2 х=2

х=1

2) 2 (х+1) + 3=3 (х-1) + 6

2 х+2+3=3 х-3+6

-х=-2

х=2

3) 3 (4-х) + 1=2 (3-х) + 6

12-3 х+1=6-2 х+6

-х = - 1

х=1

4) 7 (5-х) + 2=5 (6-х) + 1

35-7 х+2=30-5 х+1

-2 х = - 6

х=3