Linear Algebra and systems of linear equations problem

[justin_diaz]

The solution of the system
ax + ay - z = 1
x - ay - az = - 1
ax - y + az = 1

is (x,y,z) = (a,b,a). If a is not an integer, what is the value of a + b.

A) -3/2
B) -1
C) 0
D) 1/2
E) 1

Can anyone help I don't know how to approach thisOk then you get :

a^2 + ab -a = 1
a - ab - a^2 = -1
a^2 - b + a^2 = 1

I do not see how I can solve for a+ b to get an answer..

 

[Mark44]

Substitute the values for x, y, and z into your system and see what you get. Go from there.