Given a system of the form

-m1x1 + x2 = b1

-m2x2 + x2 = b2

where m1, m2, b1, and b2 are constants:

(a) Show that the system will have a unique solution if m1 != m2

(b) If m1 = m2, show that the system will be consistent only if b1 = b2

(c) Give a geometric interpretation to parts (a) and (b)

Not sure where to even begin with this, thanks in advance!