1. Solving Systems by Substitution
Notes 5.3, Date_______
Friday, November 14, 2014
9:08 AM
Solving Systems by Substitution

2. To Solve by substitution
1) Solve one equation for a variable
2) substitute
3) Solve
4) Solve for remaining variable

3. 2 3 1 4 Solve: (-x + 5) + 2x = 11 y = -2x +11 x + 5 = 11 y =-x + 5
y = -1
Solution: (6, -1)

4. 2 3 1 4 Solve: 2(-2y+2) + 3y = -1 x + 2y = 2 -4y+4+3y = -1
Solution: (-8, 5)

5. 2 3 1 4 Solve: 3(-x + 5) + 3x = 9 3y + 3x = 9 -3x+15+3x = 9 x + y = 5
15 = 9
y = -x + 5
False 4
No need to go further!!
Solution: No Solution

6. 2 3 1 4 Solve: 2(-x + 2) + 2x = 4 2y + 2x = 4 -2x+4+2x = 4 x + y = 2
4 = 4
y = -x + 2
True 4
No need to go further!!
Solution: Infinite Number of Solutions