Slides from 1-13-16
Flashback: Solve each system of equations by the
elimination method
2x + 3y = -14
4x – 3y = 2
More complicated problems
Thought Process
Example
1. Do I have variables that are
multiples of each other?
2. Do I have variables that are
opposite signs of each other?
3. Choose a variable to eliminate
and make them additive
inverses
1. 2𝑥 + 𝑦 = 12
7𝑥 + 2𝑦 = −35
2. 3𝑥 + 4𝑦 = 18
7𝑥 − 5𝑦 = 36
3. 2𝑥 − 3𝑦 = 0
3𝑥 − 2𝑦 = 5
Example 1: Solve each system of equations by the
elimination method
2x + 3y = 5
-x + 2y = 8
Example 2: Solve each system of equations by the
elimination method
3x + 7y = -33
5x – 2y = -14
Guided Practice: Solve each system of equations
by the elimination method
1. 3x – 4y = 7
2x – y = 3
2. 2x – 3y = 0
3x – 2y = 5
3. -2x + 6y = 3
x – 3y = 14
Guided Practice: Solve each system of equations
by the elimination method
1. 3x – 4y = 7
2x – y = 3
(1, -1)
2. 2x – 3y = 0
3x – 2y = 5
(3, 2)
3. -2x + 6y = 3
x – 3y = 14
No
solution
Homework
• Work on your homework; solutions may be posted online.
• Complete for a grade; we will check it tomorrow
• https://www.youtube.com/watch?v=tphSgpilNv8 – a link showing
Elimination from the YAYMATH guy