Objectives
To solve systems in three variables using elimination
To solve systems in three variables using substitution
You can represent three relationships involving three unknowns with a system of equations.
Essential Understanding To solve systems of three equations in three variables, you can use some of the same algebraic methods you used to solve systems of two equations in two variables.
You can represent systems of equations in three variables as graphs in three dimensions. The graph of an equation of the form Ax + By + Cz = D, where A, B, and C are not all zero, is a plane. You can show the solutions of a three-variable system graphically as the intersection of planes.