Go to 'Options', select 'Show: a lot of steps' and 'Apply'. This way you can get more step by step solution:

The equation that you have typed in has no solutions.

This follows from the fact that we get:

- 5 = - 8

which is contradiction.

The solution 'x' is an element of the empty set:

meaning, there are no solution for the equation: '3x+2-3x-7=2x-2x-8'