Solving Systems of Equations by Substitution

Solving Systems of Equations by Substitution

Ms. Montgomery

Woodlawn High School

Solving Systems of Equations by Substitution

The method of solving "by substitution" works by solving one of the equations (you choose which one) for one of the variables (you choose which one), and then plugging this back into the other equation, "substituting" for the chosen variable and solving for the other. Then you back-solve for the first variable.

So how does it work?

The idea is to solve one of the equations for one of the variables, and plug this into the other equation. It does not matter which equation or which variable you pick. There is no right or wrong choice; the answer will be the same, regardless. But — some choices may be better than others.

Let's watch and take notes from this video.