1. Warm- Up: Solve by Substitution
y = 2x
2x + 3y = -8
y = x + 7
2x + 3 y = 31

2. 2 Methods for Solving Algebraically
Substitution Method
(used mostly when one of the equations has a variable with a coefficient of 1 or -1)
Solve by Graphing

3. Skills Check

4. Solving Linear Systems Algebraically
EQ: How do I solve a system of linear equations by substitution?

5. Solve by Substitution
1. 2x – 3y = -2
y = -x + 4
1. (2, 2)
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6. Solve by Substitution
2. 4x + y = 0
x + 2y = -7
2. (1, -4)
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7. Solve by Substitution 3. x = -5y + 4 3x + 15y = -1 3. No solution
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8. Solve by Substitution 4. x -5y = 10 2x - 10y = 20 4. Many solutions
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9. You know how to check your answers.
Practice
Worksheet: Back side
You know how to check your answers.
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