Hi,
What answer did you get?
Here's my answer...
A=-1
B=3/2
C=1
D=-1/2
E=1/2
Using the book values, we cant seem to get the original expression when we expand it, using the above values we can, so the book must be wrong.
Sometimes books are wrong, sometimes it just looks like they are wrong at first. The only way to know for sure is to come up with a test that proves it. By expanding the two results we can find out which one comes out to the original expression. If you didnt get the results above, substitute your values into the new expression and expand it. If you dont get the original expression some way or another, it's probably not correct. If you do, then it's probably correct.