Let us take simple example:

1.   x - 2  = 5

=> x = 5 + 2   (Take -2 in right side so it becomes +2)

=> x = 7

Here LHS is x and RHS has value 7

2. x + 2 = 5 

=> x = 5 - 2   (Take +2 in right side so it becomes -2)

=> x = 3 

Here LHS is x and RHS has value 3

3.   5x - 7 = 8

=> 5x = 8 + 7   (Take -7 in right side so it becomes +7)

=> 5x = 15

=> x = 15/5

=> x = 3

Here LHS is x and RHS has value 3

4.  x/5 = 3

=> x = 5*3

=> x = 15

Here LHS is x and RHS has value 15

In this way we make LHS and RHS