7.2  Solving Linear Systems by Substitution

Mrs. Agriesti's Algebra

Examples:

Step 1:  Choose the variable to isolate.


Step 2:  Isolate the variable.




Step 3:  Replace the variable in the other equation with the expression from step 2.



Step 4:  Solve.






Step 5:  Substitute the answer you found in step 4 into one of the original equations.  Solve for the other variable.







Step 6:  Check your answers in BOTH original equations.











Step 7:  Write your answer as an ordered pair.  (Use alphabetical order.)