systems of linear equations block 44. system of linear equations a system of equations is a set or...
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System of Linear Equations
A system of equations is a set or collection of equations that you deal with all together at once.
Linear equations (ones that graph as straight lines) are simpler than non-linear equations
The simplest linear system is one with two equations and two variables.
System of Linear Equations
Graph of y = 3x – 2 & y = –x – 6
x y
1 1
0 -2
-1 -5
x y
1 -7
0 -6
-1 -5
Solution is (-1, -5)
Practice Solving Systems of Linear Equations
Solve by Graphing the following systems of linear equations (see worksheet #1):
#1
Practice Solving Systems of Linear Equations
Solve by Graphing the following systems of linear equations (see worksheet #1):
#2
Practice Solving Systems of Linear Equations
Solve by Graphing the following systems of linear equations (see worksheet #1):
#3
Practice Solving Systems of Linear Equations
Solve by Graphing the following systems of linear equations (see worksheet #1):
#4
Practice Solving Systems of Linear Equations
Solve by Graphing the following systems of linear equations (see worksheet #1):
#5
Solving Systems of Linear Equations
Substitution Method:
2x – 3y = –24x + y = 24
Choose 2nd equation: 4x + y = 24 Rewrite with single variable: y = 24 – 4xSubstitute into 1st equation: 2x – 3(24 – 4x) = –2
Solving Systems of Linear Equations
Substitution Method:
2x – 3y = –24x + y = 24
Simplify: 2x – 72 + 12x = –2 14x – 72 = -2
14x = 70 x = 5
Solving Systems of Linear Equations
Substitution Method:
2x – 3y = –24x + y = 24
Substitute x = 5 into either equation:
4x + y = 24 4(5) + y = 24 20 + y = 24
y = 24 – 20
y = 4
Solving Systems of Linear Equations
Substitution Method:
2x – 3y = –24x + y = 24
The solution is the ordered pair (5, 4).
Practice Solving Systems of Linear Equations
Solve by Substitution the following systems of linear equations (see worksheet #2):
#1
Practice Solving Systems of Linear Equations
Solve by Substitution the following systems of linear equations (see worksheet #2):
#2
Practice Solving Systems of Linear Equations
Solve by Substitution the following systems of linear equations (see worksheet #2):
#3
Practice Solving Systems of Linear Equations
Solve by Substitution the following systems of linear equations (see worksheet #2):
#4
Practice Solving Systems of Linear Equations
Solve by Substitution the following systems of linear equations (see worksheet #2):
#5
Solving Systems of Linear Equations
Addition or Elimination Method-easy:
2x + y = 93x – y = 16
Add: 5x = 25
Simplify: x = 5
Substitute: 2(5) + y = 9
10 + y = 9
y = -1
Solving Systems of Linear Equations
Addition or Elimination Method - easy:
2x + y = 93x – y = 16
Solution is (5, -1)
Solving Systems of Linear Equations
Addition or Elimination Method – medium:
2x – y = 93x + 4y = –14
Multiply 1st by 4: 8x – 4y = 36
8x – 4 y = 363x + 4y = –14
Solving Systems of Linear Equations
Addition or Elimination Method – medium:
8x – 4 y = 363x + 4y = –14
Multiply 1st by 4: 8x – 4y = 36
Add: 11x = 22
Simplify: x = 2
Substitute: 2(2) – y = 9 4 – y = 9
-y = 5 or y = -5
Solving Systems of Linear Equations
Addition or Elimination Method – medium:
2x – y = 93x + 4y = –14
Solution is (2, -5)
Solving Systems of Linear Equations
Addition or Elimination Method – hard:
4x – 3y = 25 –3x + 8y = 10
Multiply 1st by 3: 12x – 9y = 75
Multiply 2nd by 4: -12x + 32y = 40
Solving Systems of Linear EquationsAddition or Elimination Method – hard:
12x – 9y = 75
-12x + 32y = 40
Add: 23y = 115
Simplify: y = 5
Substitute (original equation) : 4x – 3y = 25
4x – 3(5) = 25
4x = 40
x = 10
Solution is (10, 5)
Practice Solving Systems of Linear Equations
Solve by Addition/Elimination the following systems of linear equations (see worksheet #3):
#1
Practice Solving Systems of Linear Equations
Solve by Addition/Elimination the following systems of linear equations (see worksheet #3):
#2
Practice Solving Systems of Linear Equations
Solve by Addition/Elimination the following systems of linear equations (see worksheet #3):
#3
Practice Solving Systems of Linear Equations
Solve by Addition/Elimination the following systems of linear equations (see worksheet #3):
#4