Exercise 40 Page 79

Equations written in slope-intercept form follow a specific format. y=mx+ b In this form, m represents the slope of the line and b represents the y-intercept.

Identifying Slope and Intercept

Since the given equation is not in slope-intercept form, let's rewrite it so that it will be easier to identify the slope and y-intercept.

Below we highlight the slope m and y-intercept b. y=2/3x - 4 ⇔ y=2/3x+( -4) The slope is 23. The y-intercept is -4, so the graph crosses the y-axis at the point (0, -4).

Graphing the Equation

A slope of 23 means that for every 3 units we move in the positive horizontal direction, we move 2 units in the positive vertical direction. m=2/3 ⇔ rise/run=2/3 To graph the equation, plot the y-intercept and then use the slope to find another point on the line.