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Coordinates,Distance and Midpoint

Linear Inequalities

The Graphical Method

Substitution & Elimination

Solving Systems Using Matrices

Problem Solving

Systems of Inequalities

Systems with 3 Equations in 3 Unknowns

Review&Test

UNIT 2  : SYSTEMS OF EQUATIONS

LESSON 4 :  SOLVING SYSTEMS USING SUBSTITUTION OR ELIMINATION

 

 

Methods of Solving Systems

 

The Substitution Method:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note:  Use the method of substitution if the coefficient (number in front of) of one of the variables is 1.

 

Rectangular Callout: Strategies for Substitution Method.
§	Isolate one of the variables if it has a coefficient of 1.
§	Substitute this isolated variable in the other equation.
§	Solve for the remaining variable.
§	Substitute the value of the solved variable in one of the original equations.
§	Solve for the second variable.

          

 

 

 


The Elimination by Addition or Subtraction Method:

 

 

 

 

Rectangular Callout: Strategies for Elimination by Addition or Subtraction Method.
§	Find the LCM for the coefficients of either x or y.  This will be the common coefficient.
§	Multiply both equations by appropriate numbers to obtain this common coefficient.
§	Add the 2 equations if the coefficients have the different signs.
§	Subtract the 2 equations if the coefficients have the same sign.
§	Solve for the remaining variable.
§	Substitute the value of the solved variable in one of the original equations.
§	Solve for the second variable.

 

 

 

 


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