$2.$ Use the Transpose and Append commands, to construct the augmented system, $[$A$|$b$].($Note: the Append command applied to A and b appends b as a row of A$,$ so you will have to append b to the transpose of A and then take the transpose of the appended result.$)$ Use the RowReduce command to get the row$-$reduced echelon form of the augmented system. What is the rank of A$?$ What is incomplete with the results of Problem $1?$