1. Systems of Equations can be linear or non-linear
Can be solved by substitution or elimination:
(A) x = y (B) 2x – y = (C) y = 3x y = x x + 2y = y = 2x + 6
And of course graphing…. to check. In this chapter some solutions can only be shown with equations or graphs.

2. Linear Systems can have . . .
One solution, infinite no solution solutions:
consistent consistent inconsistent independent dependent

3. Linear Equations can have . . .
One solution, no solution or infinite solutions:
Try these:
A B C
4x = 8y x = 8y y = -3x + 2
x - 2y = x - 2y = x + 3y - 6 = 0

4. Non-linear Systems Use substitution
We did 9.1 # You can use #119 and the student solution manual. Also see example 12.

5. Joint variation
Problem 140 page 718

6. What you need to know from 9.1:
Use the elimination and substitution methods.
Write your solutions!
Solve application problems: 113 to 133
Joint variation and functions in two variables. 137 to 146