# Linear Functions: ax+by=c

The general form for a line is where and are integers.

How does it work? Video

Using either the slope intercept form ( ) or the general form ( ) we can calculate all the critical values of a straight line. These are: the intercept, the intercept and the slope.

Example 1: convert to form: Example 2: convert to general form: # Finding the y intercept

The y intercept is the point where the line cuts the y-axis. The x coordinate is zero. To find the y intercept, we substitute for .

Example 3: Find the y intercept of the line  # Finding the x intercept

The x intercept is the point that is on the line and on the x axis. The y coordinate is zero. To find the x intercept, we substitute for .

Example 4: Find the x intercept of the line  # Calculations

Example: Video (3:31 mins)

5 Examples for this applet: Video (16 mins)

Examples for this applet on a pdf: Examples x y intercepts slope general form

Calculate the x and y intercepts and the slope. Rewrite the equation in the alternate form. Use fractions or terminating decimals, don’t round decimals.