Math 224-01: Differential Equations: Reading Homework 7.1

1. Linear Systems of Differential Equations : what do we do in this chapter?
   
   1. Lead Modeling : how do we make a model for the lead in the body?
      
   2. Changes to the Model : how is a reduction in lead in the environment modeled? how is the addition of medication modeled?
      
      1. Point : what is step(t), anyway?