Page 103 - Math Course 3 (Book 1)

The Slope-Intercept Form

Mo. 3

Lesson 6 Let’s Begin

KEY CONCEPTS:
1. Determine slopes and y-intercepts of lines. Find the Slope and y-Intercept
2. Graph linear equations using the slope and
y-intercept.
Example

State the slope and the y-intercept of the graph of
1
MO. 3 - L6a y = x + 3
2
Determine Slopes and y = x + 3 Write the original equation.
1
y-intercepts of Lines 2
1
y = mx + b m = , b = 3
2
Vocabulary A-Z
1
Let us learn some vocabulary Answer The slope of the graph is , and
2
the y-intercept is 3.

y-intercept Write an Equation in Slope-Intercept Form

The y-intercept is the y-coordinate of a point where Example
the graph crosses the y-axis.

State the slope and the y-intercept of the graph of
–4x + 5y = –10.

–4x + 5y = –10 Write the original
y = 2x + 1 equation.

–4x + 5y + 4x = –10 + 4x Add 4x to each
side.
Slope = 2
y-intercept = 1
5y = –10 + 4x Simplify.

4
y = –2 + x Divide each side
5 by 5.
slope-intercept form
4
The slope-intercept form is an equation written in y = x + (–2) Write the equation
in slope-intercept
the form y = mx + b, where m is the slope and b is 5 form.
the y-intercept.
4
y = mx + b m = , b = –2
y = mx + b 5
4
Slope y-intercept Answer The slope of the graph is and
5
they-intercept is –2.

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