This is a really basic question. I want to prove the following statment:

If a linear system is changed to another by multiplying both sides of an equation by a nonzero constant, then the two systems have the same solution.

I know this is very obvious and seemingly pointless to prove. However, I never have been able to tackle the concept of proof and I can rarely figure out how to begin on things like this.

This is my linear system:

The solution set is an n-tuple . Where would I go from here?