This document contains notes from a math lesson on solving systems of linear equations using substitution. It includes: 1) An assignment of math problems due the next day 2) Examples of graphing linear equations 3) An explanation of the substitution method for solving systems of linear equations along with steps to follow 4) Examples of using substitution to solve several systems of linear equations 5) A word problem about finding two numbers whose sum is 180 and difference is 24

1. Lesson 6­2.notebook
Assignment:
1­­>L6.2, pg. 345, #2­22 (evens) ­ due Tomorrow (11/15)
November 14, 2013

2. Lesson 6­2.notebook
November 14, 2013
Lesson 6.2 WarmUp:
Graph the following equations.
y = x ­ 3
1)
2)
y = ­x ­ 3
3)
y = 2x + 4
4)
y = ­3x + 2
5)
y = ­1/2x + 2

3. Lesson 6­2.notebook
November 14, 2013
Lesson 6.2:
*Another method for solving a system of linear equations is called
substitution.
**Steps for using SUBSTITUTION:
­­solve one equation for one variable (isolate 1 variable)
­­substitute the new equation into the other equation for the
isolated variable; then solve the equation
­­then substitute the value from step 2 into either equation and
solve for the other variable
­­write the solution as an ordered pair
[check the solution in both equations!]

4. Lesson 6­2.notebook
November 14, 2013
Lesson 6.2 examples:
Use substitution to solve the system of equations.
A) y = 2x + 1
3x + y = ­9
B)
x + 2y = 6
3x ­ 4y = 28

5. Lesson 6­2.notebook
November 14, 2013
C)
y = 2x ­ 4
­6x + 3y = ­12
D)
2x ­ y = 8
y = 2x ­ 3

6. Lesson 6­2.notebook
E)
y = 4x ­ 6
5x + 3y = ­1
November 14, 2013

7. Lesson 6­2.notebook
November 14, 2013
G) The sum of 2 numbers is 180 and the difference between them is 24. Find the
2 numbers.