Step-by-step explanation:

- In the line 2, only variables were operated with a reduction of similar terms in each side of the equation, giving as result -4x at one side, and 2x at the other side.
- In the line 3, terms with variables were joined together in one side of the equation, and then, they were operate it, given as result -6X.
Pick any digit except zero. Write it four times on the same line. If you want to, put a comma between the first and the second one. Shazam ! There's your number !