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Do Now. Algebra II. Solving Linear Systems. Main ways of solving. Substitution Elimination Graphing We will focus on 1 and 2 today. First Method: Substitution. 1) Pick an equation and isolate a variable. 2) Plug value from step 1 into the second equation. Solve.
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Algebra II Solving Linear Systems
Main ways of solving • Substitution • Elimination • Graphing We will focus on 1 and 2 today.
First Method: Substitution 1) Pick an equation and isolate a variable. 2) Plug value from step 1 into the second equation. Solve. 3) Plug value of the variable from step 2 into any equation. Solve. 4) Final answers is a coordinate: (x, y)
Substitution Example 1.) x + 2y = 6 3x – 2y = 2
Substitution Examples 2.) 4x + y = 7 3.) x + 3y = 3 2x + 5y = -1 2x – 4y = 6
Substitution Examples 4.) 2x – 3y = 3 5.) 2x – 5y = 9 -2x + y = -4 -3x + y = -7
Second Method: Elimination 1) Change equation(s) so that you have opposite coefficients for one of the variables. 2) Add equations straight down. Solve. 3) Take value of the variable from step 2 and plug into any equation. Solve. 4) Final answer is the coordinate (x, y).
Solve the system using elimination 1.) x – y = 7 2x + y = 5
Solve the system using elimination 2.) x + 2y = -11 3x – 2y = -1
Solve the system using elimination 3.) 3x – y = 4 2x + 3y = 32
Solve the system using elimination 4.) 2x + 5y = 0 4x + 6y = 24
Solve the system using elimination 5.) 3x – 4y = -4 -5x + 2y = 2
Homework • Systems of Linear Equations Worksheet • # 5-8, 15-18