Depending on the equation there can be three possible cases: 1- There can be 1 specific solution for the variable: 2x+4= 3 where x= -1/2 2- there can be an infinite amount of solutions: 2x+x-2=3x-3+1 where x=x 3- there can be no answer: 3+2x-x=5-3x+4x where the solution doesn't exist