Goal: Eliminate variables until there is one left. How?
 Multiply equation by a constant (not zero)
 Add/subtract equations together
 Plug the calculated value of variable in one of the equations to find value of other variable
 Double check your work by plugging the values back into the equation
Tips for 3 equations with 3 variables:
 Eliminate x’s first from the 2nd and 3rd equation
 Eliminate y in 3rd equation
It’s easier to visually understand elimination. We will go through one example step by step.
Here’s an example (click here):
1. Multiply top equation by 3 and the bottom equation by 5
To get:
2. Subtract
3. Solve for y

4. Plug and chug to get x
5. Double check
Here’s another example with two equations (click here):
Here’s an example of three equations with three variables (click here):
*Remember to use the tips for solving this type of system of linear equations!
Solving a system of equations using elimination is pretty simple. Keep your work clean, double check your work for small errors, and practice a couple problems. Elimination is a very popular method to solve systems of linear equations before learning about matrices, so it is important to practice it.
Until next time,
Leah
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