How do you solve #12r-18=13r+18#?
Re-arrange the equation by moving all the like terms to one side and the numbers or constants to the other side.
Use additive inverses to remove a term from a side where you do not want it. Do the same operation on each side of the equation.
Simplifying both sides gives:
Note that by moving the variable to the right side, we ended up with a positive variable.
Otherwise we would have ended up with