Determine the values of a for which the following system of linear equations has no solutions, a unique solution, or infinitely many solutions. You can select "always', 'never, 'a', or 'a , then...

Extracted text: Determine the values of a for which the following system of linear equations has no solutions, a unique solution, or infinitely many solutions. You can select "always', 'never, 'a', or 'a , then specify a value or comma-separated list of values. 3x+3xz+9x3 - -9 X1+x2+6x3 - -9 -2x1+axz-7x3 - 9 No Solutions: Always Unique Solution: Always Infinitely Many Solutions: Always