Answer:
a) If
and
. The system has no solution
b) If
and a different to 2, we have a unique solution.
c) If
and
we have infinitely solutions.
Explanation:
We need to rewrite the third equation in terms of a and z to solve this.
Let's start solving the first equation:
(1)
If we subtract z in both side of this equation we will have:
(2)
Now we can put the equation 2 into the last equation:

(3)
Simplifying the equation 3 we have:
(4)
Now we can analyzes the equation 4 for each case:
a) If
and
. The system has no solution
b) If
and a different to 2, we have a unique solution.
c) If
and
we have infinitely solutions.
I hope it helps you!