formula for line parallel to another line

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santaclaus
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formula for line parallel to another line

Postby santaclaus » Thu Mar 12, 2009 1:26 am

Find a formula for the line parallel to the line y=20-4x and containing hte point (3,12)

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stapel_eliz
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Postby stapel_eliz » Thu Mar 12, 2009 2:14 am

santaclaus wrote:Find a formula for the line parallel to the line y=20-4x and containing hte point (3,12)

To learn about the relationships between parallel and perpendicular slopes, try this lesson on slope.

To learn how to use a point and a slope to find the equation for a line, try this lesson on line equations.

:D

santaclaus
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Re: formula for line parallel to another line

Postby santaclaus » Fri Mar 13, 2009 8:49 pm

so, after the lesson I read, could I solve this by saying that -4 is the slope parallel? I don't know how to use the point (3 and 12) to think of an equation y=mx +b? or y-y1 = -4(x-x1) and if I solve, i get y-12 = -4x+12 and then get y= -4x +24????

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stapel_eliz
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Postby stapel_eliz » Sat Mar 14, 2009 12:00 am

santaclaus wrote:so, after the lesson I read, could I solve this by saying that -4 is the slope parallel?

Yes; parallel lines have the same slope.

santaclaus wrote:I don't know how to use the point (3 and 12) to think of an equation

Try using the methods explained and demonstrated in the lesson on straight-line equations (in the link provided earlier). :wink:

santaclaus wrote:i get y-12 = -4x+12 and then get y= -4x +24????

I think you did the following:

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. . . . .

. . . . .

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If so, your method is fine! :D


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