Demonstrate that the system is consistent by verifying any one of the four sample solutions provided. Then because $n=9>6=m$, Theorem CMVEI gives us the conclusion that the system has infinitely many solutions. Notice that we only know the system will have at least $9-6=3$ free variables, but very well could have more. We do not know know that $r=6$, only that $r\leq 6$.