Solve each of the following by Cramer’s rule:

2x - y &= 1
5x - y - z &= -7
3x + 2z &= 6
end{align*} ]
a) x = 2, y = -3, z = 1
b) x = -1, y = 4, z = 2
c) x = 3, y = 1, z = -2
d) x = 0, y = 2, z = 3