5x-5×

1

3

=0.8
      5x-

5

3

=

4

5

    5x+

5

3

-

5

3

=

4

5

+

5

3

         5x=

12

15

+

25

15

         5x=

37

15

      5x×

1

5

=

37

15

×

1

5

          x=

37

75