Determine whether the following statements are true or false and provide a justification for your response.
If the coefficient matrix of a linear system has a pivot in the rightmost column, then the system is inconsistent.
If a linear system has two equations and four variables, then it must be consistent.
If a linear system having four equations and three variables is consistent, then the solution is unique.
Suppose that a linear system has four equations and four variables and that the coefficient matrix has four pivots. Then the linear system is consistent and has a unique solution.
Suppose that a linear system has five equations and three variables and that the coefficient matrix has a pivot position in every column. Then the linear system is consistent and has a unique solution.
Austin, Understanding Linear Algebra, §1.4 Pivots and their influence on solution spaces, Exercise 4