Determine if the following linear systems have a unique exact solution (in which case, find it), an infinite set of exact solutions (in which case, find an expression for these), or no solution. Work through these problems by hand, though feel free to use software to check your answers.
(a)
6x - 4y + 2z = 28
0x + 2y + 6z = 0
(b)
0x + y - z = 0
0x + 4y + 0z = 2
(c)
16x + 2y + 3z + 5w + 11u + 10v + 8a + 9b + 7c + 6d + 12e + 4f + 14g + 15h = 1
4x + 0y + 0z + 0w + 0u + 0v + 0a + 0b + 0c + 0d + 0e + 0f + 0g + 0h = 4