N1
 13-100х=0
                                      N2
 8-0,8х=0
                                      N3
  7х-4=х-16
                                     N4
 1,3р-11=0,8р+5

 

13-100х=0

-100х=13-0

х=13/(-100)

х=-0,13
                                    
 8-0,8х=0

-0,8х=8-0

х=8/(-0,8)

х=10
                                     
7х-4=х-16

7х-х=-16+4

6х=-12

х=-12/6

х=-2
                                   

1,3р-11=0,8р+5

1,3р-0,8р=5+11

0,5р=16

р=16/0,5

р=32

1)

13-100х=0

 -100х=-13

   х=-13:100

     х=-0.13

2)

8-0.8х=0

-0.8х=-8

х=8:(-0.8)

х=10

3)

7х-4=х-16

7х-х=-16+4

6х=-12

х=-12:6

х=-2

4)

1.3р-11=0.8р+5

1.3р-0.8р=5+11

0.5р=16

р=16:0.5

р=32