Define T: P1 --> P1 by

T(ax + b) = (2b - a)x + (b + a)

Show that T is both one-to-one and onto, and find the inverse transformation to T.

This problem showed up in my homework, and I'm not sure how to finish it. I was able to prove that T is both on-to-one and onto, but don't know how to find T^(-1). I hope someone can help. Thanks in advance!