After Theorem 1.5 we note that multiplying a row by 0 is not allowed because that could

Question:

After Theorem 1.5 we note that multiplying a row by 0 is not allowed because that could change a solution set. Give an example of a system with solution set S0 where after multiplying a row by 0 the new system has a solution set S1 and S0 is a proper subset of S1. Give an example where S0 = S1.