Matrix Variables: Solving Mx = b with 2-D Vectors

[EvLer]

if I am given this to solve:
Mx = b
where M
[0 0]
[1 2]
[0 0]
[3 6]

and b = [b1, b2, b3, b4]^t

does that mean I have vector x as 4 elements, i.e. x1-x4 or just x1 and x2?

thanks

edit: oh, wait... rank is 2, so its only x1 and x2, right?

 

[cristo]

Your vector will be x=[x₁ x₂]^T

 

[EvLer]

oh, didn't refresh in time... thanks :)