Thank you for the opportunity to help you with your question!

-3=x+x+x The first task you want to accomplish is to put like terms together. The right side of the equation has 3 like terms because they are all terms of x. x+x+x = 3x just as 1+1+1=3. The equation now becomes...

-3=3x

Now divide both sides by 3. -3/3=-1 and 3x/3=x

-1=x

This is the solution.

Please let me know if you need any clarification. I'm always happy to answer your questions.