11/19/2014
5-7
Point-Slope Form
• Questions on 5-6
• L to J
• Lesson 5-7
5-7
Point-Slope Form
"The definition of insanity is doing the same
thing over and over expecting a different result”
– Point-Slope Form
In lesson 5-6 you saw that if you know the
slope of a line and the y-intercept, you can
graph the line. You can also graph a line if you
know its slope and any point on the line.
• Assignment 5-7
Upcoming:
HWQ # 12 – Thurs. 11/20
Chapter 5 test – Fri. 11/21
Holt Algebra 1
5-7
Point-Slope Form
Example 1A: Using Slope and a Point to Graph
Holt Algebra 1
5-7
Point-Slope Form
Example 1B: Using Slope and a Point to Graph
Graph the line with the given slope that contains
the given point.
Graph the line with the given slope that contains
the given point.
slope = 2; (3, 1)
slope =
Holt Algebra 1
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Point-Slope Form
; (–2, 4)
Holt Algebra 1
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Point-Slope Form
Example 2: Writing Linear Equations in Point-Slope
Form
Write an equation in point-slope form for the line
with the given slope that contains the given point.
C.
A.
B.
Holt Algebra 1
Holt Algebra 1
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11/19/2014
5-7
Point-Slope Form
5-7
Check It Out! Example 2
Write an equation in point-slope form for the line
with the given slope that contains the given point.
a.
Example 3: Writing Linear Equations in SlopeIntercept Form
Write an equation in slope-intercept form for
the line with slope 3 that contains (–1, 4).
b. slope = 0; (3, –4)
Holt Algebra 1
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Point-Slope Form
Holt Algebra 1
Point-Slope Form
5-7
Check It Out! Example 3
Write an equation in slope-intercept form for
the line with slope that contains (–3, 1).
Point-Slope Form
Example 4A: Using Two Points to Write an Equation
Write an equation in slope-intercept form for
the line through the two points.
(2, –3) and (4, 1)
Holt Algebra 1
5-7
Add 1 to both sides.
Point-Slope Form
Example 4B: Using Two Points to Write an Equation
Write an equation in slope-intercept form for
the line through the two points.
(0, 1) and (–2, 9)
Holt Algebra 1
Holt Algebra 1
5-7
Point-Slope Form
Example 5: Problem-Solving Application
The cost to stain a deck is a linear function
of the deck’s area. The cost to stain 100,
250, 400 square feet are shown in the
table. Write an equation in slope-intercept
form that represents the function. Then
find the cost to stain a deck whose area is
75 square feet.
Holt Algebra 1
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11/19/2014
5-7
Point-Slope Form
5-7
Point-Slope Form
Check It Out! Example 5
Homework:
What if…? At a newspaper the
costs to place an ad for one
week are shown. Write an
equation in slope-intercept
form that represents this linear
function. Then find the cost of
an ad that is 21 lines long.
Holt Algebra 1
Pages: 345-347
21-41 odd, 43-44
49-50, 59-60
Holt Algebra 1
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