October 25, 2012
Lesson 4.5
Point-Slope Form
y −y
Since m =
x −x
2
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m(x − x ) = y − y or y − y = m(x − x )
2
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2
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We call y − y = m(x − x ) the point-slope
form of a linear equation.
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If we are given the slope of a line and the
coordinates of any point on the line, we can write
its equation using this form. Sometimes we will
change this result to slope-intercept form to
make it easier to graph.
Write the equation of a line with slope -3 passing
through the point (-9, 6) using the point-slope form
of a linear equation. Change the equation to slopeintercept form.
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The Standard Form of a linear equation
is Ax + By = C, where A, B, and C are real
numbers. We are going to want A, B, and
C to be integers and A > 0.
Write the equation of the line through the points
(-5, 6) and (-2, 7) in standard form.
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Find the equation of the line with m = -3
and passing through the point (5, -6). Write
the equation in point-slope form and then
change it to slope-intercept form. Use your
calculator to graph the equation.
Use y − y = m(x − x )
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Find the equation parallel to
and through the point (4, 0).
Graph each line in the same window.
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Write an equation of the line with x-intercept
2 and slope of .
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Write an equation for each line graphed below.
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