Substitution VS. Elimination

Both of these methods are used algebraicly for finding solutions of 2 equations of lines.

Step 1: Pick ONE equation & re-arrange so it is x=____ or y=____

Step 2: Substitute this into the OTHER equation (use brackets!)

Step 3: Solve equation

Step 4: Substitue the number just found back into the re-arranged equation (refer to step 1)

*Note: If there are no terms with coefficients of 1, will have to work with fractions.

Step 1: Add or subtract (preferably add) both equations together

Step 2: Find x or y variable

Step 3: Plug found variable into either original equation to find the other variable

*Note: we always want to create a ZERO PAIR with both equations. Might have to re-arrange equations before hand.

When we have finished solving for both variables using substitution and elimination, we can VERIFY the solutions by plugging the coordinates into both original equations.