1. Review: 8.2a Mini-Quiz
1. Use substitution to solve the system of equations.
2. Use substitution to solve the system of equations.
3. Use substitution to solve the system of equations.

2. Class Greeting

3. Chapter 8 Systems of Linear Equations and Inequalities
Lesson 8-2b
Solving Systems Equations by Substitution

4. Objective: Students will solve real world word problems involving how to solve a system of linear equations using substitution.

5. Geometry
Find an equation of the line with slope m = -3 and passing through the intersection of the lines x - y = 0 and x - 2y = 5.
Write the equation, use y = mx + b.
3x - y = 0
x - 2y = 5
m = -3 and (x, y) = (-1, -3)
x = 2y + 5
-3 = -3(-1) + b
3(2y +5) – y = 0
-3 = 3 + b
6y + 15 – y = 0
b = -6
5y = -15
m = -3 and b = -6
y = -3
Answer:
The equation is y = -3x – 6.
3x – (-3) = 0
x = -1
So, the line with slope m = -3 passes through (-1, -3).

6. Lesson Summary: Objective: Students will solve real world word problems involving how to solve a system of linear equations using substitution.

7. Preview of the next Lesson: Objective: Students will learn how to solve a system of linear equations using elimination.

8. Homework
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9. Stand Up Please