Download 4.2 Graphing linear equations

4.2 Graphing linear
equations
Objective: Graph a linear equation using a table of values
Linear Equations

A linear equation in x and y is an equation that can be written in the form
Ax + By = C

Note: A and B are not both zero.

A solution of an equation in two variables is an ordered pair (x,y) that makes
the equation true.
Check Solutions of Linear Equations

Determine whether the ordered pair is a solution of x + 2y = 5

(1,2)

(7, -3)
Practice

Determine whether the ordered pair is a solution of 2x + y = 1.

(-3,7)

(3, -7)
Function Form

A two-variable equation is written in function form if one of its variables is
isolated on one side of the equation.

Example: y = 3x + 4 is in function form.
2x + 3y = 6 is NOT in function form
Find Solutions of Linear Equations

Find three ordered pairs that are solutions of -2x + y = -3
Practice

Find three ordered pairs that are solutions of 3x + y = 4
Graphs of Linear Equations

The graph of an equation in x and y is the set of all points (x,y) that are
solutions of the equation.

The graph of a linear equation can be shown to be a straight line.
Graph a Linear Equation

Use a table of values to graph
y = 3x – 2
Graph a Linear Equation

Use a table of values to graph
y = – 2x + 1
Practice
Use a table of values to graph
4y – 2x = 8
Practice
Use a table of values to graph
2x – y = 7