example of "For every b ∈ R7, the system ATx = b is consistent" 1. The problem statement, all variables and given/known data "For every b ∈ R7, the system ATx = b is consistent" I'm not sure if this is the right place to post this question. There's isn't a subsection known as 'general math' for me to post. What does the above statement implies? Any examples?