Systems of Linear Equations Lesson  #4

solving systems of Linear Equations by Elimination

 

-The method of elimination. This method is particularly useful when the equations involve fractions.

 

Step1. If necessary, multiply each equation by a constant to obtain coefficients for x (or y) that are identical (except perhaps for the sign).

Step2. Add or subtract the two equations to eliminate one of the variables.

Step3. Solve the resulting equation to determine the value of one of the variables.

Step4. Substitute the solution into either of the original equations to determine the value of the other variables.

 

Q, Consider the system of equations:

3x+9y=27

3x+4y=12

A. x=0

y=3