How can you solve an equation with a variable on ni tu sides?

  Subtract from both sides of the equation the term you don't want

Step-by-step explanation:

In solving equations, you generally want to "undo" operations that are done to the variable. Addition is "undone" by adding the opposite (that is, subtracting the amount that was added). Multiplication is "undone" by division.

If you have variables on both sides of the equation, pick one of the variable terms and subtract it from both sides of the equation.

Example

  2x = x +1

If we choose to subtract x, then we will have a variable term on the left and a  constant term on the right:

  2x -x = x -x +1 . . . . . . . x is subtracted from both sides

  x = 1 . . . . . . simplify

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Note that we purposely set up this example so that removing the variable term from the right side caused the variable term and constant term to be on opposite sides of the equal sign. It may not always be that way. As long as you remember that an unwanted term can be removed by subtracting it (from both sides of the equation), you can deal with constant terms and variable terms no matter where they appear.

Additional Comment

It usually works well to choose the variable term with the smallest (or most negative) coefficient. That way, when you subtract it, you will be left with a variable term that has a positive coefficient.