when working out an equation, if the result comes out like : x = 2, or y = 4.....a variable equal to a number, then there is 1 solution
if the result comes out like : 0 = 4, or 2 = 6...no variable and an incorrect result, then the equation has no solutions because ur lines are parallel.
if the result comes out like : 2 = 2 or 5 = 5...no variable and a true statement, then there will be infinite solutions because ur lines are coincident...they are the same line
