body{margin:0;} noscript{z-index: 10000; position: fixed; display: block; height: 100%; width: 100%; background: #fff;} noscript .fa{font-size: 40px; display:block; color: #daa520;} noscript div{margin-top: 6%; padding-left: 20px; padding-right: 20px; text-align: center;} ! You must have JavaScript enabled to use this site.

Dashboard

Pearson Algebra 2 Common Core, 2011 View details

3. Linear Functions and Slope-Intercept Form

Continue to next subchapter

Exercise 41 Page 79

What information does a slope-intercept form equation give you?

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.

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.

4x+5y=20

SubEqn

LHS-4x=RHS-4x

5y=-4x+20

DivEqn

.LHS /5.=.RHS /5.

y=-4/5x+4

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.

Subchapter links

Lesson Check p.78

Practice and Problem-Solving Exercises p.78-80

Standardized Test Prep p.80

Mixed Review p.80

Exercise 41 Page 79

Hints

Check the answer

Practice exercises

Asses your skill

Identifying Slope and Intercept

Graphing the Equation