# Mathematics- Solving a system of equations with 3 variables, Sept. 10, 2008

Today we looked at solving a system of equations with three variables and three functions. We used the same methods that we used in solving a system of 2 equations:

1) Graphing
2) Making equal
3) Substitution
4) Elimination

The main difference is that there is an additional step; we must eliminate one of the variables first to reduce the system of equations into 2 equations with 2 variables before we can proceed with the method we used prior. A worked example was done in class and will be posted shortly.

The solution to a system of equations (x, y, z) will tell you the point of intersection of the 3 planes (each equation represented a plane). For homework, please complete the starred questions on the worksheet handed out today. Please make sure you bring the worksheet to class tomorrow as we will continue to work from this text.

Included below is a scan from the other grade 11 text. You can click on it to see a worked example that they’ve done (we’ve done the same one in class) with explanations to how they solved for it. 