6.2 Substitution

Document Sample
6.2 Substitution Powered By Docstoc
					       6.2 Substitution

               Objective:
A) Solve systems of equations by using
              substitution
B) Solve real world problems involving
    systems of equations by using
              substitution
       Substitution

A method of finding an
 exact solution of a
 system of equations
 Steps for solving a system of
   equations by Substitution
Step 1: When necessary,
 solve at least one
 equation for one variable
   Step 2: Substitute the
resulting expression from
   Step 1 into the other
  equation to replace the
 variable. Then solve the
         equation.
   Step 3: Substitute the
  value from Step 2 into
either equation, and solve
  for the other variable.
 Write the solution as an
       ordered pair.
Example 1- Solve the System of
         Equations
         y = 2x + 1
         3x + y = -9
Example 2- Solve the System of
         Equations
       y = 4x –6
      5x +3y = -1
               You Try
Page 345 #1 and 2
Solve and then Substitute
       Example 1

      x + 2y = 6
     3x – 4y = 28
Example 2- Solve and Then
       Substitute
     4x + 5y = 11
     y – 3x = -13
  You Try

Page 345 # 3
No Solution or Infinitely Many
          Solutions
         Example 1
           y = 2x –4
        -6x + 3y = - 12
Example 2- Solve the System of
         Equations
          2x – y =8
          y = 2x - 3
               You Try
Page 345 #4 and 5
 Write and Solve a System of
          Equations
Page 344
A store sold a total of 125 car stereo systems
  and speakers in one week. The stereo
  systems sold for $104.95, and the speakers
  sold for $18.95. The sales from these two
  items totaled $6926.75. How many of
  each item were sold?
       Homework

Page 345 # 9 to 22 odd,
 Skip 15

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:2
posted:3/23/2013
language:English
pages:16