Let's solve the equations.
1.
Since by solving the equation we get an equality that always hold the equation has an infinite number of solutions.
2.
Since this is a contradiction the equation does not have a solution.
3.
Therefore, this equation has one solution.
4.
Therefore, this equation has one solution.
5.
Since by solving the equation we get an equality that always hold the equation has an infinite number of solutions.
6.
Since this is a contradiction the equation does not have a solution.