No, it does not. You may not reproduce, show (e.g pictures or videos of), etc. another's copyrighted material--period and end of sentence. If you can do this without ever showing the problem or example, it would be legal: but if you in any way reproduce or show (or even verbally/orally state or recite) another's copyrighted content, even if you sold the customers the book, you will be in violation of copyright and could be sued.I used to work for a supplemental text book company that also created online practice materials: we always created our own content, rather than using material from, say, the classroom's main text, specifically to avoid infringement.