1. After the denominator of the fractional equation is removed, the coefficient of unknown x in the integral equation is 0, and then the integral equation has no solution, so the original equation has no solution.

From the coefficient of unknown x in the whole equation is 0, the value of unknown letters can be found.

2. After the denominator is removed from the fractional equation, the coefficient of unknown x in the integral equation is not 0, but the solution of the integral equation is rooted, so the original equation has no solution.

Substitute the added root into the whole equation and find the value of the unknown letter.

The ninth question above is only used in the second case, and the denominator is removed: x-3=-m to find the root x = 2；; m= 1。

Some questions have the above two situations.