In the trial and error method, different values are taken for the variable to find which value solves the equation.

A trial and error method is done by assuming different values for the variables to find which value solves the equation.

For example: x + 5 = 7.

To find the solution by trial and error method we have to put different values of x, so LHS and RHS become equal.

Choose x = 0, => 0 + 5 = 5$\ne$7, so x = 0 is not the solution.

Choose x = 1, => 1 + 5 = 6 $\ne$7, so x = 1 is not the solution.

Choose x = 2, => 2 + 5 = 7 = 7, so x = 2 is the solution.

Therefore, x = 2 is the solution for x + 5 = 7.