In this puzzle from my book Fun with Savannah (for the well-rounded puzzler who wants to know more.) the student will "write an essay" with the help of some systems of 2 equations/2 unknowns. The student will solve the systems by using linear combinations (elimination method) and thus provide the numbers needed for the essay.
Magnolia Madness, An Essay on Magnolias through Linear Systems
by Jay Waggoner, Value Added Publishing
is licensed under a Creative Commons Attribution-NoDerivs 3.0 Unported License