First, we must combine similar terms. If we move -17 to the right hand side as +17 and Qx to the left hand side as -Qx, we obtain,
if we factorize x, we obtain
We can see that the equation has no solution if we obtain a contradictory result.
For instance, if P is equal to Q, we have
which is an absurd result. Then, if P = Q the equation has no solution for any x