1. REVIEW OF 3-1 AND 3-2
A) Solve by graphing
y = 2x – 1
y = -3/4x + 10
B) Solve by substitution
y = 2x – 1
3x + 4y = 40
C) Solve by elimination
-2x + y = – 1
3x + 4y = 40

2. The systems of equations in Example 2 have exactly one solution
The systems of equations in Example 2 have exactly one solution. However, linear systems may also have infinitely many or no solutions. A consistent system is a set of equations or inequalities that has at least one solution, and an inconsistent system will have no solutions.
You can classify linear systems by comparing the slopes and y-intercepts of the equations. An independent system has equations with different slopes. A dependent system has equations with equal slopes and equal y-intercepts.

4. Example 3: Classifying Linear System
Classify the system and determine the number of solutions.
x = 2y + 6 D) E)
4x + y = 1
y + 1 = –4x
3x – 6y = 18

5. Example 6: Real World Application
F) A movie theater has tickets where the child tickets are $3 and adult tickets are $7. Last night they sold 345 tickets for a total of $ How many child and adult tickets were sold?

6. Example 7: Real World Application
A movie theater has tickets where the child tickets are $4 and adult tickets are $6. Last night they sold 520 tickets for a total of $ How many child and adult tickets were sold?