Would this have been marked correct?

[Gringo123]

I had to expand the brackets in this expression:
2f[d+e+f]-2e[d+e+f]

My answer is:
2df + 2f² -2de - 2e²

The answer in my book is the same but all the components are in different places:
-2e² +2f² -2de + 2df

Would my answer have been ok in an exam?

 

[Mentallic]

Yes, definitely!

If you would have had any marks deducted, your teacher has issues.

 

[Borek]

http://en.wikipedia.org/wiki/Commutativity

 

[snshusat161]

Mentallic is right but it doesn't follow in every case but looking at your standard (may be class II) it is always right for you. In higher classes you will find something different. Like in vector multiplication A x B is not equal to B x A. similarly you'll find that A + B is not equal to B + A. But don't worry about it today.

 

[Gringo123]

Thanks a lot folks!