1) 4x+5 меньше или = 21;

2) 9x-7 больше - 25;

3) 4x+2 больше 3x+1;

4) 6x+1 меньше 2x+9;

5) 10/x-4=2;

6) 6-5y/2=-4.5;

7) 2y+1/3=5;

8) 6.2/3y+1=2.

1) 4x+5≤21

4x≤21-5

4x≤16

x≤16/4

x≤4

2) 9x-7>-25

9x>-25+7

9x>-18

x>-18/9

x>-2

3) 4x+2>3x+1

4x-3x>1-2

x>-1

4) 6x+1<2x+9

6x-2x<9-1

4x<8

x<8/4

x<2

5) 10/x-4=2

10/x=2+4

10/x=6

10=6x

x=10/6=5/3=1 (2/3)

6) 6-5y/2=-4,5

-5y/2=-4,5-6

5y/2=10,5

y=10,5 * (2/5) = 2,1*2=4,2

7) 2y+1/3=5

2y=5-1,3

2y=3,7

y=3,7/2=1,85

8) (6,2/3) * y+1=2

(6,2/3) * y=2-1

(6,2/3) * y=1

y=3/6,2=3*10/62=30/62=15/31

1) 4x+5 меньше или = 21;

4x< = 21-5

4x<=16

x< = 4

2) 9x-7 больше - 25;

9x> - 25+7

9x> - 18

x> - 2

3) 4x+2 больше 3x+1;

4x+2>3x+1

4x-3x>1-2

x>-1

4) 6x+1 меньше 2x+9;

6x-2x<9-1

4x<8

x<2

5) 10/x-4=2;

10/x=2+4

10/x=6

10=6x

x=10/6

x=1 4/6 = 1 2/3

6) 6-5y/2=-4.5;

-5y/2 = - 4.5-6

5y/2 = 10.5

5y=21

y = 21/5=4 1/5

7) 2y+1/3=5;

2y = 5-1/3

2y = 15/3-1/3

2y = 14/3

y = 14/3 : 2

y = 14/3 * 1/2

y = 7/3 = 2 1/3

8) 6.2/3y+1=2

6.2/3y=2-1

6.2/3y=1

6.2=3y

y=3 : 6.2

y = 30/62

y = 15/31