LE4 - ask about free/bound variables

[StevenClontz]

I'd like to see more information on students' choice of free/bound variables. Maybe these prompts:

a. Explain how to find a simpler system that has the same solution set.
b. Explain how to choose appropriate free and bound variables.
c. Explain how to describe the solution set using set notation.

[siwelwerd]

Rather than ask your part (b), I'd rather tweak the solution sets so that the appropriate free variables have nonzero coefficients in multiple places. Then, they will run in to trouble if they choose inappropriate bound variables.

To accomplish this, on the backend side non-pivot columns should have multiple nonzero entries.

Separately, we may wish to ensure there are always multiple free variables.