Grade 8 · Unit 4~48 min2 topics · 3 videos

Linear Functions

Dig into linear functions. You'll calculate slope as rise over run, write equations in slope-intercept form (y = mx + b), and graph lines and interpret what the slope and intercept mean.

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Work through these

Topics in this unit

Each topic is a short page: read the walkthrough, watch the video, try the practice, then take a quick quiz. Go in order or jump to what you need.

Slope

Measure steepness as rise over run.

2 videos
Practice
2-question quiz
~24 min

Slope-Intercept Form

Read slope and y-intercept straight from y = mx + b.

1 video
Practice
2-question quiz
~24 min

Goals

Learning objectives

By the end of this unit, you should be able to:

Find the slope of a line from a graph or two points.
Write linear equations in slope-intercept form, y = mx + b.
Graph linear equations using slope and y-intercept.
Interpret slope as a rate of change and the y-intercept as a starting value.

Key vocabulary

Slope: The steepness of a line: rise over run, or change in y over change in x.
y-intercept: Where a line crosses the y-axis; the value of y when x = 0.
Slope-intercept form: y = mx + b, where m is the slope and b is the y-intercept.
Rate of change: How much one quantity changes for each unit change in another.

More practice

External resources

Hand-picked links from Khan Academy and trusted worksheet libraries.

Khan Academy

Linear functions practice

Open resource

Math Worksheets 4 Kids

Slope worksheets

Open resource

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