Exercise 41 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=-4/5x+ 4 The slope is - 45. The y-intercept is 4, so the graph crosses the y-axis at the point (0, 4).

Graphing the Equation

A slope of - 45 means that for every 5 units we move in the positive horizontal direction, we move 4 units in the negative vertical direction. m=-4/5 ⇔ rise/run=-4/5 To graph the equation, plot the y-intercept and then use the slope to find another point on the line.