Applying Systems of Linear Equations

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Applying Systems of Linear Equations

• Assignment 15 6.5 WB Pg. 81 1 9 all

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Determining the best method

• 6.1 Graphing to estimate solutions (since
  graphing usually doesnt give an exact solution).
• 6.2 Substitution If one of the variables in
  either equation has a coefficient of 1 or -1 (it
  is easy to solve one equation for one of its
  variables).
• 6.3 6.4 Elimination Anytime.

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Heres a method called graph and check

• Basic steps 1. Put each equation into
  slope intercept form (yMxB) 2. Graph the
  two lines (M is your slope B is your
  Y-intercept) 3. Find the point that the lines
  appear to intersect at, and then put that
  solution into EACH equation and solve to check
  for accuracy.

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Solving Linear Systems by Substitution

• Basic steps
• 1. Solve one equation for one of its variables
• 2. Substitute that expression into the other
  equation and solve for the other variable
• 3. Substitute that value into first equation
  solve
• 4. Check the solution

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Solving Systems by means of Elimination

• Basic steps 1. Arrange the equations with
  like terms in columns
• 2. After looking at the coefficients of x and
  y, you need to multiply one or both equations by
  a number that will give you new coefficients for
  x or y that are opposites.
• 3. Add the equations and solve for the unknown
  variable
• 4. Substitute the value gotten in step 3 into
  either of the original equations solve for other
  variable
• 5. Check the solution in both original equations