5.2 Solving System of Equations Using Substitution

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5.2 Solving System of Equations Using Substitution

• Objectives
• -- To solve systems of equations algebraically
  using the substitution method

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Substitution Method

• This method allows you to find exact solutions to
  systems.
• Solve one of the equations of the system for one
  of the variables. (It doesnt matter which
  variable you solve for)
• Substitute that expression into the other
  equation, replacing the variable that you solved
  for
• This leaves an equation with one variable
• Solve this equation for the variable to get its
  value
• Take that value and substitute it back into one
  of the ORIGINAL equations of the system to find
  the value of the second variable
• 6. Check to make sure that the ordered pair
  works in BOTH equations of the system

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Examples

• Solve when a system
  has both
• equations
  solved for the same variable, set the two
  expressions equal to each other.
• one
  variable, solve for it
• _____________
• 
  divide both sides by 10
• 
  substitute into one of
• the
  originals to find d
• The
  solution is (0.02, 1.2)
  

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Solve
5
Solve
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Solve