This document provides instructions and examples for solving systems of linear equations by substitution. Students are told to isolate a variable, substitute it into the other equation, solve for the remaining variable, and check their solutions using graphs. Five example problems are shown to demonstrate this process.

1. Algebra 1
7.2
Chapter 7: Solving Systems of Linear Equations
Section 2: Solving Linear Systems by Substitution Pg. 405 – 410
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Use substitution to solve the system Use a graph to check your solution:
 y = x− 3
1. 
 4 x + y = 32
a.) Solve an equation for a variable (isolate one variable).
b.) Substitute the expression for the variable in part “a” into the other equation and solve for
the other variable.
c.) Substitute the value of your known variable into the first equation and solve for the other
variable.
d.) Write your solution as a coordinate. How can you check the solution?
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 x+ y = 9
2. 
 2x + 5 y = 30

2. Algebra 1
7.2
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 3x − y = 0
3. 
y= 6
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 x + 4 y = 300
4. 
 x = 2y
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 2x + y = − 4
5. 
 x − 2y = − 7
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3. Algebra 1
7.2
 2x − y = − 2
6. 
 4x + y = 5