For each system, determine whether it has a unique solution (in this case, find the solution), infinitely many solutions, or no solutions.

1.
** A. ** No solutions** B. ** Infinitely many solutions** C. ** Unique solution: ** D. ** Unique solution: ** E. ** Unique solution: ** F. ** None of the above

2.
** A. ** Unique solution: ** B. ** Unique solution: ** C. ** Unique solution: ** D. ** No solutions** E. ** Infinitely many solutions** F. ** None of the above

3.
** A. ** Unique solution:** B. ** Unique solution: ** C. ** Infinitely many solutions** D. ** No solutions** E. ** Unique solution: ** F. ** None of the above

4.
** A. ** Unique solution: ** B. ** Infinitely many solutions** C. ** No solutions** D. ** Unique solution: ** E. ** Unique solution: ** F. ** None of the above

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