Core Connections Geometry, 2013
CC
Core Connections Geometry, 2013 View details
2. Section 9.2
Continue to next subchapter

Exercise 85 Page 561

What information does the slope-intercept form of an equation give us?

Graph:

y-intercept: (0,6)
x-intercept: (4,0)

Practice makes perfect
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. Let's identify these values in the given equation.

y= -3/2x+ 6 The slope is - 32. The y-intercept is 6, so the graph crosses the y-axis at the point (0, 6).

Graphing the Equation

A slope of - 32 means that for every 2 units we move in the positive horizontal direction along the graph, we move 3 units in the negative vertical direction. m= -3/2 ⇔ rise/run=-3/2 To graph the equation, plot the y-intercept and then use the slope to find another point on the line.

Finding the x-intercept

Lastly, we need to find the x-intercept. Looking at the graph we made, it seems that point (4,0) might be a good candidate. Let's check it by substituting the point into the given equation. If simplifying the equation results in a true statement, we know that this is the x-intercept.
y = -3/2x+6
0 ? = -3/2( 4) +6
0 ? = - 12/2 + 6
0 ? = - 6 + 6
0 = 0 âś“
Since we have a true equality, the point (4,0) lies on the graph of the equation and is the x-intercept.