There is no solution. p - 4 = -9 + p We add -p to both sides p - 4 = -9 + p -p -p --------------- -4 = -9 When all variables are eliminated from an equation, and what is left is a false statemenr, then that means there is no solution. Such an equation is called "a contradiction". When all variables are eliminated from an equation, and what is left is a true statement, that that means there are infinitely many solutions. --------------------------------------------- Suppose we had had x + 3 = 3 + x x + 3 = 3 + x -x -x --------------- 3 = 3 That is true so there are infinitely many solutions. That is called "an identity". Edwin