I'm searching for hard and creative problems in basic algebra related (but not limited) to factoring polynomials and identities for my students.
Iv'e collected problems in these books, but what I need is a huge collection of hard and unseen problems in high school algebra:
-Problem Solving Strategies by Arthur. Engel
-101 Problems in algebra by Titu Andreescu and zuming Feng
-Introduction to Algebra by Richard Rusczyk
unfortunately most of the problems in those books are well-known to my students and cannot feed their hunger...
I should mention that my students are about 13 and 14 and are really talented and most of them know those books.
I'm looking for great and unknown books with huge collections of hard and original problems on High School Algebra or Olympiad level Algebra...